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The remarkable progress achieved in hop breeding in Huell, one of the world leading hop research centers, is based on the wide variability of genetic resources available including worldwide wild hop germplasm. The new Huell hop cultivars are characterised by their improved, broad resistance/tolerance to the most common diseases with low application of pesticides, their fine aroma and/or high alpha acid contents and increased yield. New breeding programs focus on hops adapted to low trellis systems or plants with a high content of e.g. specific health-promoting or anti-oxidative polyphenols. The “Berlin Program” of the German Brewing Barley Association offers the opportunity to select the best new varieties at an early stage for their agricultural, malting and brewing criteria by means of field trials, micromalting and –brewing and pilot brews in an industrial scale. Thus, the introduction of new promising varieties could be reduced by approx. 2 years, an economic advantage for breeders and farmers as well as for the industry. In the last decade the most successful German brewing barley varieties were cultivated in more than 11 European countries. They allow considerable cost saving malting and mashing techniques due to their faster modification and higher enzymatic power. It has to be pointed out that this progress in hop and barley breeding has been achieved without the application of genetic engineering. In the near future, innovative selection techniques using molecular markers for quality and resistance will support and speed up breeding of even more competitive varieties in hop and barley.

 

 

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Description of topic: The economist Milton Friedman famously argued that the business of business is business, and that companies keen on philanthropy should maximise shareholder returns and let those individual shareholders decide which philanthropies are the worthiest.
However, what is the business of business in the age of globalisation? How can multinational brewing companies operate in cultures with different laws, norms and values, with investors scrutinizing their every measure in case it (negatively) impacts the bottom line, all the while stakeholders want to see action and not just words?
Materials and methods for data collection: The issue of sustainable development is not a passing fad. It implies more than just adding a few energy saving light bulbs and turning down the taps in the toilets. Sustainability needs to be taken seriously - and therefore out of the hands of the hands of slick marketers who are hired to spin and churn token good deeds into glossy end products printed on recycled paper with none-toxic ink.
Results: This paper will show that for almost a decade now brewing companies have grappled with the issue of corporate social responsibility - which aims to define what businesses are responsible for and what they should do to secure long-term growth (read: “sustainable development”). More driven by circumstance than being drivers of change, brewers have had to realise that even if they do more than what the law requires, society’s expectations of their social responsibilities have increased.
Discussion: The debate has been very much narrowed down to two major, mutually exclusive aspects: On the one hand, there seems to be an urge to pin down the “true nature”, the “substance” or “core” of corporate social responsibility. This can be regarded as an attempt to answer the question: “What is CSR?” Hence discussions revolve around the borders of responsibility: like, “Is it enough to improve a brewer’s environmental performance?”.

 

What is new - Exploring and accepting one’s corporate social responsibility is both a challenge and an opportunity, as brewers find themselves increasingly under pressure from both outside and within to be more open, more communicative and - more accountable for a wide range of actions.

 

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Description of topic: Statistical tools have been used in breweries since approx. year 1900 successfully. After 1945 use of CI has gained momentum, and since 2000 have been intensively used at large brewing groups to achieve competitiveness.
Materials and methods for data collection: Literature search.
Interviews.
Results: Without increasing manning, leading breweries are now achieving lower manufacturing costs, less waste, less energy - and electricity consumption, higher extract yields and speedier processes.
Discussion: Is CI old wine on new bottles?
Is CI in reality just common sense?
CI has, in names of TPS, TQM, TPM, Six Sigma, TPS and LEAN dominated the CI work at the leading breweries in the world.

What is new - Continuous Improvement (CI) has in brewery management improved the performances of processes, quality of beer and at the same time reduced costs. CI has, impressively, also increased the quality of jobs.

 

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Description of topic: As the industry consolidates there is a clear distinction emerging amongst leading multinational brewers in their interactions with the media.
One approach is characterised by those who remain pro-active, viewing contacts with journalists as beneficial and as a means to push out positive stories from behind the mash tun and into the public domain.
The other, increasingly evident, approach is to keep media contacts to the minimum as with market-required financial announcements. It is easier to control the message than ever before, what with pseudo-interviews with corporate leaders on web-based services such as Cantos in London, and phone-in presentations that remove the journalist from the subject.
There is a case to be made that despite occasional journalistic sensationalism the brewing industry by-and-large has a positive story to tell and more to gain from a proactive attitude than fear from being open and honest with journalists. Think of work with indigenous barley farmers in India and sub-Saharan Africa, work with alcohol abuse prevention community programmes worldwide, and efforts to upgrade environmental performances - there are hundreds, thousands, of story possibilities for each and every brewing concern. This paper would review examples of best practice, and suggest fruitful avenues of story developments working both independently and in co-operation with journalists. It would also review the rise of new internet journalism, the cult of the amateur writer turned pundit thanks to blogs, home websites, etc.
Materials and methods for data collection: Analysis of press releases, financial comments, press conferences, video presentations issued by leading national and multinational brewers.
Examination of press reports, both print and electronic.
Results: To be determined.
Discussion: To be determined.

What is new - The proposed paper may seem a tad unorthodox for a scientifically-oriented brewing conference but as most, if not all, delegates will have on-going contacts with the media during their careers it could of great value to examine the brewing industry´s relationship to the press, and vice versa.

 

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The nature of the brewing industry continues to change in the first decade of the 21st century. The challenge for the brewery laboratory is not only to foresee the future, but to enable the company’s technical future. Approaches that have involved basic research and an instrument focus were successful in the past. However, these approaches are less appropriate in the new business environment, where a greater emphasis is placed on cost and timeliness. In response to the changing environment, a solution-focus approach is needed, where efforts are evaluated on their merit to produce practical, robust solutions. To achieve this, the laboratory needs to be staffed with personnel who are not only technically skilled, but can act as business-savvy knowledge-brokers capable of directing problem solving efforts. Therefore, the role of the organization, people, and the use of outside resources needs to be re-evaluated. In the future the approach to problems will rely more heavily on treating brewing processes as black boxes, using a solution focus and sharing knowledge. Examples of the traditional and solution-based approach for yeast performance and beer freshness will be discussed. Another important function of the laboratory is to capture institutional knowledge and make it readily available. This can be achieved through web-based tools that aid in trouble-shooting production issues. Ultimately the technical future will be enabled by quickly generating simple, cost effective solutions.

 

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Description of topic: The goal of this work is to better understand and manage the appearance and establishment of Fusarium langsethiae on brewing barley. We have acquired data concerning this mould, on the basis of complementary competence (epidemiology, etiology, toxicology, molecular biology), from barley culture (study of the growth and the etiology of the contamination to the field) to the finished products.

Materials and methods for data collection: Study of the barley infection stage by Fusarium langsethiae was achieved by artificial contamination in the field, in experimental parcels, so as to be as close as possible to common agricultural practice. Artificial contamination was achieved by spraying spores at different development stages. Notation of the infection was made during the culture as well as DNA and T2/HT2 toxins quantification. Malting studies were made by quantification of total Fusarium DNA, Fusarium langsethiae DNA and T2/HT2 toxins during the malting process, in order to assess the potential development of the this and other species.

Results: Symptoms and T2/HT2 toxins appeared during the culture at the stages around flowering. Within the spikelets, some seeds stopped their growth and turned black. We have shown that these seeds contains high amount of T2/HT2 toxins. During the malting process, most of Fusarium DNA and T2/HT2 toxins are washed out at the steeping step, but an increase of DNA during the germination step is the proof that viable fungi can be a threat because of subsequent toxin production.

Discussion: Numerous articles are available concerning wheat contamination period by Fusarium Head Blight in field but few data are available concerning the barley infection stage by Fusarium langsethiae. The experiments we have set up show that contamination occurs after flowering either at the level of appearance of symptoms and the increase of T2/HT2 toxins but the infection is not systemic. During the malting process, presence of mycelium and/or spores on kernels is sufficient to lead to an increase in DNA and toxin

What is new - The barley infection stage by Fusarium langsethiae was not known, up to now, neither the symptoms of the infection. The potential of growing and toxin production during the malting process rises interrogation on the survival of field fungi during the storage.

 

 

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Description of topic: Fusarium mycotoxins are the toxic secondary metabolites produced by fibrous fungi of the Fusarium genus. They can contaminate a wide spectrum of cereals (wheat, barley, maize, rice), cereal-based products (malt, beer, bread, breakfast cereals) and also feedstuffs. They can be detected in free form, but nowadays also as altered masked form. Little is known about the occurrence, bioavailability and further transformations of some of these bound compounds, which additionally also escape usual analytical detection techniques used for routine control. This issue is not only brewers and maltsters issue, but responsibility has all cereal sector and future limits can influence all of us. Masked mycotoxins (especially deoxynivalenol-3-glucoside) have been largely discussed recently, because they can influence possible EU mycotoxin limits for cereals and cereal-based product. Materials and methods for data collection: Standards of analysed mycotoxins (deoxynivalenol, T-2 toxin, HT-2 toxin, deoxynivalenol-3-glucoside, nivalenol, fusarenon-X, sum of 15- and 3-acetyldeoxynivalenol, zearalenone). High performance liquid chromatography coupled with mass spectrometer was used for the analysis. Identification and quantification of analytes was performed using a tandem in time mass spectrometry (MS/MS). Also Enzyme-linked immunosorbent assay (ELISA) was used for quick screening of mycotoxins. Results: Free and masked Fusarium mycotoxins were monitored in beer production chain. Cross-reactivity of deoxynivalenol-3-glucoside of commercial ELISA test kits was found. Discussion: Mycotoxins as deoxynivalenol, T-2 toxin, HT-2 toxin, nivalenol, fusarenon-X, sum of 15- and 3-acetyldeoxynivalenol, zearalenone and nowadays new masked form as deoxynivalenol-3-glucoside detected in raw materials, can play potential risk for contamination of cereal-based food and beverages. Mineralisation of these free and hidden toxins in foodstuffs play crucial role for human health. What is new - Masked Fusarium mycotoxins identification and monitoring during malting

 

 

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Description of topic: Amines play important physiological roles: they are essential for cell proliferation and growth; they have psychoactive and vasoactive functions, however a high amine level within the blood is an hazard for human health and some of them have a sensory impact on foods and beverages.
In beer the presence of amines is affected by several factors such as the raw material, the brewing technology and the presence of decarboxylase -positive microorganisms. Our purpose is to verify whether amines can be considered as chemical descriptors to differentiate the brewing products.
The content of amines in all-malt and adjunct worts with different hops products was detected before and after high gravity bottom fermentation in industrial scale processes
Materials and methods for data collection: The amines: putrescine, cadaverine, histamine, tyramine, spermidine and spermine were detected by reversed-phase HPLC with fluorescence detection after derivatization with dansyl-cloride .
All the data have been subjected to Microsoft Excel 2003 and to one-way analysis of variance (ANOVA) and to Principal component analysis (PCA). Statistical elaboration was carried out by SPSS software version 13.0 (SPSS Inc., Chicago, Illinois).
Results: The highest total amine levels were detected in adjunct worts. Differences in single amine were found in all malt and adjunct worts. In comparing fermented and none fermented worts no significant changes in biogenic amine was found except for 2 samples in which 40 - 50% increases ware detected.
The PCA discriminates the adjunct from all-malt products and links the adjunct worts to putrescine, cadaverine, histamine, tyramine.
The all-malt samples were separated in correlation to the different hop products.
Discussion: The data are promising and we are still working on a larger number of samples to validate these preliminary results.  
What is new - It is the first approach to a pattern recognition technique using the content of biogenic amines as chemical descriptor to differentiate raw materials and beer styles and to find out irregular processes.

 

 

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Description of topic: Barley grains are always rich in microbes. The multitude of microbes actively interacts with the barley kernels, and thus has great effects on the properties of the final malt and beer. Although the knowledge of microbes associated with barley and malting ecosystem is increasing, only little is known about the structures of complex microbial communities in the barley tissue. This study investigated the formation and the ultrastructure of microbial biofilms in malting.
Materials and methods for data collection: We investigated the complex associations between the microbes and grain tissues during barley processing using ultra-high resolution scanning electron microscope with cold cathode field emission electron source (FESEM). Malting experiments were carried out with and without Lactobacillus plantarum culture added into the steeping.
Results: Microbial cells and fungal hyphae were located between the testa and outer epidermis of the barley kernels. The soaking of barley during the steeping phase invigorated microbial growth and production of exocellular polymeric substances (EPS). The EPS matrix covered up to 90% of the surfaces in the outer layers of barley. Several microbes expressed appendages anchoring the cells to the kernel tissues and to each other, resulting in dense networks underneath the outer epidermis. The production of an amorphous EPS matrix was greatly reduced by application of Lactobacillus plantarum as a starter culture. The high-gravity mashing and Büchner-filtration tests showed that the wort separation was 30% more efficient when L. plantarum was applied. Suppression of EPS-producing bacteria by L. plantarum during the steeping could partly explain this difference.
Discussion: Microbial biofilms are an integral component of the barley malt. The high density of bacteria and EPS may partly explain the poor filtering properties sometimes experienced with the malted barley. Our results indicate that the use of protective cultures in malting may reduce the formation of EPS and thereby improve wort separation.

What is new - This is the first report that visualises the structure and changes of microbial biofilms in barley malting and associates exopolysaccharide production with mash separation.

 

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Description of topic: With this research funded by the European Hop Research Council (EHRC) and Scientific Fund of the German brewing industry (Wifö) new efforts have been started to support powdery mildew (PM) resistance breeding in hop.
Materials and methods for data collection: After contact with the pathogen,cDNA-AFLP based transcript profiles of resistant and susceptible hop varieties have been analyzed. Gene expression analysis was carried out using PM resistant and susceptible hops. Resistant and susceptible plants were inoculated with powdery mildew spores and leaf material from these plants was harvested at different times and frozen in liquid nitrogen. Subsequently the mRNA was isolated from the leaf samples, transcribed into cDNA and used for cDNA-AFLP analysis.
Results: The analysis of expressed genes in PM resistant and susceptible plants revealed specific fragments of genes (TDFs= transcript-derived fragments) which were only expressed in resistant hops several hours after contact with PM. Thus, it was assumed that these newly expressed fragments are involved in the defence reaction to powdery mildew which starts 4 to 24 hours after contact with the pathogen. These TDFs were isolated and finally sequenced. These sequences were compared with already known resistance genes in other crops. Based on detected sequence similarities it was deduced that several TDFs in these studies are involved in the defence or resistance reaction to PM. From several differentially expressed TDFs sequence homology to genes involved in the resistance reactions of other crops to various fungi could be identified.
Discussion: cDNA-AFLP based markers are highly informative and much more reliable than classical AFLP markers, because these markers describe gene sequences expressed during the resistant reaction with sequence homology to defense-related genes in other crops. At current for these TDFs with sequence homology to resistance genes SNP (single nucleotide polymorphism) markers should be developed which are more effective for a molecular selection process.

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Description of topic: The malting process can be defined as an ecosystem consisting of barley and the diverse microbial community associated with the grain. Recent developments in molecular biology have opened new possibilities for monitoring this complex ecosystem. Traditionally, biological events related to malting have been monitored by analysing enzymes or metabolites. In many cases malting could also be monitored by analysing the expression of the genes that control these events. VTT has developed a high-throughput method TRAC (transcriptional profiling with affinity capture) that can be used to monitor the expression of tens of genes simultaneously. The method was applied to simultaneously analyse the activities of barley and microbes during malting.
Materials and methods for data collection: The TRAC method was used to study the expression of a selection of barley genes related to germination and Fusarium genes involved in trichothecene biosynthesis and growth. Gene expression was followed during the micro-malting of heavily contaminated barley as well as barley from which fungi were inactivated by heat treatment before steeping. TRAC-probes were designed using available sequence data. Malt analyses were performed using standard methods. Quantitative analysis of trichothecenes was performed with LC-MS/MS.
Results: The gene expression of both barley and Fusarium fungi were detectable during malting. Strong expression of Fusarium genes was detected in steeping. The expression pattern of genes related to both fungal growth and trichothecene biosynthesis changed when fusaria were inactivated before malting.
Discussion: Successful application of the TRAC method relies on the specificity of the probes. Today, sequence data for barley and fusaria are limited. However, this data is constantly improving as genomes are being sequenced. The method will be further developed to enable the detection of gene expression related to events such as production of enzymes.

What is new - For the first time, a range of barley and fungal activities were analysed simultaneously from the same sample, using transcriptional profiling.

 

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Description of topic: Gushing is a term used to describe spontaneous overfoaming of beer on opening of the packaged product, and it is often associated with heavy Fusarium infection of barley and malt. Our studies have indicated that fungal proteins called hydrophobins act as the gushing factors of beer, although other mechanism maybe involved in the gushing phenomenon. Hydrophobins are small, moderately hydrophobic proteins that are produced and secreted by filamentous fungi. This presentation gives a critical review of the current knowledge on hydrophobins and their relation to gushing. Furthermore, the fate of hydrophobins in the malting and brewing process will be discussed. New data on characterisation of hydrophobins from F. graminearum and the related species are presented.
Materials and methods for data collection: Samples collected from the pilot and industrial processes were analysed using the hydrophobin ELISA. Gushing potentials of malts were analysed using the Carlsberg gushing test. We searched F. graminearum genome database of predicted proteins with generated statistical profile hidden Markov models for hydrophobins. The best matching sequences and the corresponding genes were isolated and characterised. The putative hydrophobin genes were cloned and expressed in Trichoderma reesei.
Results: Fungi produced hydrophobins in the field and during malting. Mashing process released hydrophobins from the malt and some of the hydrophobins survived the brewing process to end up in the beer. We found five hypothetical proteins with high sequence similarity to hydrophobins in the F. graminearum genome database. One putative hydrophobin gene was expressed in T. reesei and a hydrophobin was isolated from the culture filtrate of the transformant. Highly similar hydrophobin genes were also found from the genomes of the other Fusarium species.
Discussion: Fusarium fungi produce several hydrophobins which are able to induce beer gushing. Fusarium fungi produce hydrophobins in the field and during malting. Hydrophobins may end up in the beer.

What is new - Data on characterisation of hydrophobins from a gushing active fungus F. graminearum and the related species are new.

 

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Description of topic: Gushing, the spontaneous overfoaming of beer, is a very grave quality problem for the breweries concerned. Especially problematical is the primary gushing resulting from the raw materials since it cannot securely be prevented by technological procedures. Despite intensive efforts, research has not yet been able to fully clarify the complex interrelationships involved in the gushing phenomenon. Above all, the affect of technological parameters during the malting and brewing processes has been insufficiently investigated.
Materials and methods for data collection: Barleys with varied degrees of Fusarium infestation were malted on a 1-kg scale. At various stages during the malting, the development of important Fusarium species were observed and quantified with the help of specific PCR primers. Changes to the gushing potential during the malting process were analysed using the Modified Carlsberg Test. Brewing trials on a 2-l scale were designed in order to obtain beers, with a high gushing risk, from contaminated malts in the laboratory under reproducible conditions. In these trial brews, the effect of technological parameters on the gushing potential of the beers was examined.
Results: Malts with a high gushing risk have a greatly increased Fusarium contamination. Heavy gushing could be induced using otherwise inconspicuous control malts spiked with low quantities of contaminated material. Large changes to the gushing potential could be observed during the malting process. Especially critical phases are steeping and withering. Possibilities to reduce the gushing risk by technological means during malting are discussed. In brewing trials the gushing potential of the beers could be influenced, amongst others, by high temperature boiling, lowering the pH, pasteurisation or the use of proteolytic enzymes.
Discussion: The results presented are a further step towards an improved understanding of the gushing phenomenon and provide valuable indications for a possible manipulation using technological means in the maltings and brewery.

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Description of topic: Gushing has been a concern in the european malting and brewing industry in 2007/2008 . Fungal infection of barley, in particular by species of Fusarium, was known to cause beer gushing. Malting barley from harvest 2007 gave a high number of malt positive gushing and beer gushing without correlation with mycotoxins content. The aim of this investigation was to isolate and identify the main fungi that contaminated malting barley and malt, and to test their gushing and mycotoxin potential.

Materials and methods for data collection: Identification of fungi by visual and PCR method. Production of artificially contaminated malting barley by pure fungi strains Gushing potential test on barley and malt Analysis of fungi mycotoxins by HPLC-MS/MS

Results: Different fungi strains that contaminated malting barley from harvest 2007 were isolated and identified. The main fungi were F. graminearum, F. culmorum, F. paoe, F. Langsethiae, F. avenaceum, F. tricintum, F. moniliformine, Miccrodochium nivale, Alternaria ssp. Gushing potential and mycotoxins production were carried out with several strains of each species isolated from malting barley. All strains of each Fusarium species produced different kind of mycotoxins but were not gushing positive. Alternaria gave slightly gushing sample positive on other and all strains of Miccrodochium nivale that produced no mycotoxins gave highly gushing positive samples.

Discussion: Our study with artificially contaminated malting barley produced in sterile condition showed that fusarium species are not responsible for gushing but miccrodochium nivale. These results corroborate with high percentage of malting barley sample from harvest 2007 contaminated by Miccrodochium nivale and also no correlation between DON and gushing barley or malt.

What is new - It was showed for the first time that miccrodochium nivale, fungi malting barley contaminant is responsible for gushing.

 

 

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Description of topic: The interactions between polyphenols and proteins have been identified as the main reaction system for haze formation in beer. Nevertheless chill haze or permanent haze formation can be observed in stabilized beer (PVPP / silica gel) after a certain storage time. It is also well known that the presence of oxygen, higher temperature, light, metallic ions and mechanical influences accelerate the haze formation during storage, but the responsible reaction mechanism could not be enlightened satisfactorily up to now. Also the described approach according to an oxidation reaction which activates polyphenols by generating ortho-chinons is not able to explain haze formation in stabilized beer completely.
Materials and methods for data collection: Several analytical methods (ESR - liquid and solid measurements 77 K , gel electrophoresis, ICP-OES,..) has been used to characterize the composition of chill and permanent haze.
Results: Our investigations on detached haze by solid measurements using ESR at 77 K have shown ESR signals in haze, which can not be found in filtrate. The different ESR-signals are caused by stabilized organic radicals and ions like Fe3+. These results indicate an interrelation of haze formation with the Fenton reaction system. The comparison of the “Endogenous Antioxidant Potential (EAP)” decrease and haze formation during shelf life showed an important coherence. At the achievement of the EAP zero value the formation of radicals and Fe3+, Cu+ ions from the Fenton- and Haber-Weiss reaction system are extremely increasing and chill haze formation in beer starts with a deceleration of 1-2 warm (40 °C) and cold days changes. With higher oxygen and iron content in beer the EAP decreases faster and haze formation starts earlier.
Discussion: The analytical methods have clearly demonstrated that oxidative processes under contribution of the Fenton- and Haber-Weiss system are a major cause for haze formation in stabilized beer. On the basis of former postulated haze theories a mechanism was mapped out.

What is new - After the consumption of the EAP, the reactive OH• and secondary radicals are generated by the catalysis of iron and copper ions. At the same time the formation of Fe3+,Cu+ ions and the formation of stabilized organic radicals in oxidized iron-polyphenol-protein-complexes occur. Due to the complex formation the development of chill haze can be observed. During beer aging the iron-polyphenol-protein-complexes react with each other by attendance of radical reactions and formation of covalent bonds

 

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Description of topic: Foam stability studies have often examined hop acids singly for their foam stabilizing effect, however many brewers utilize dual systems of foam stabilizers. In this study, foam stabilizing properties and cling formation patterns of lager beer to which iso-alpha-acid (Iso), tetrahydro-iso-alpha-acid (Tetra), hexahydro-iso-alpha-acid (Hexa), and propylene glycol alginate (PGA) were added were investigated.
Materials and methods for data collection: Four series of base beers were prepared to achieve approximately 0, 4, 8, and 12 ppm of Iso in lager beer. A second hop acid, Tetra or Hexa, or PGA was added to these base beers over a commercially relevant concentration ranges. Foam stability was measured using a NIBEM Foam Stability Tester (NIBEM-T) and a Steinfurth Foam Stability Tester (Steinfurth-FST) while foam cling was measured using NIBEM Cling Meter (NIBEM-CLM).
Results: The magnitude of foam stabilizing power of each compound was dependent on the test employed, especially in the case of PGA. The foam stabilizing effects of these compounds were found to be additive for both NIBEM and Steinfurth measurements, though FSF results showed somewhat hyperbolic tendency. In identifying equi-foam stability concentrations among the 4 compounds, the substitution of 1 ppm of Tetra or Hexa yielded the same improvement of foam stability as adding 28 ppm PGA. Using Steinfurth FSF values this substitution equality changed to 1 ppm of Tetra or Hexa in place of 4.8 ppm of PGA. NIBEM-CLM measurements revealed that PGA had a minimal effect on cling formation while Tetra and Hexa concentrations as low as 1 ppm showed significant improvement to foam cling adherence.
Discussion: Both the NIBEM and Steinfurth methods yielded results indicating all foam stabilizers (Tetra, Hexa and PGA) had a statistically significant effect on improving foam stability in beers that had already been dosed with Iso; however, the magnitude of the differences in compounds was significantly influenced by the type of test employed.

 

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Description of topic: Foam stability is, beside the sensory stability, one of the hottest topics of today brewery research. The usual approach to improve beer head is to look for its components, describe them, design a test to asses them, conclude which raw materials are richer in these components and can bring more of them to the beer. Although these results are usually very interesting, the real usability of such results is quite limited, because it is a number one priority of any brewery to keep all other quality parameters of the beer unchanged.
Materials and methods for data collection: Matrix foaming potential was measured with Foam stability tester type FA (1-CUBE, Czech republic). Foam stability of finished beers was measured with NIBEM analyzer (Haffmans, Germany)
Results: Twelve different beer samples from the market were tested for basic analytical composition and foam stability. Although lower in proteins, higher foam stability of none-alcoholic beers compared to lagers indicate that the key to stable foam doesn’t necessarily have to be only in the high content of foam positive proteins.
Discussion: Because the foam success is much more complex and the ratio of protein / hop acids / fat is of greater importance than simple content of any of these, it can be more helpful to analyze directly the foam properties of matrixes over the production line to study the possibilities of foam improvement.

What is new - Discussion of advantages of “black box” foam analytics via “matrix foaming potential” measurement compared to detailed complex analytical studies of foam-positive compounds for foam studies in brewery quality control.
Foam stability improvement possibilities reappraisal from the point of view of brewery that is limited by its traditions, e.g. in raw materials.

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Description of topic: The understanding of the necessity of cleaning but lack of practice is a quite common game in selling draft beer. Without any doubt, hygiene is a crucial parameter for sales success in the draft beer scene. But the obvious question is, how much care is essentially needed and furthermore which kind of care is leading to a sufficient level of quality? Instead of an unverified assumption, scientific investigations are needed to answer these questions. This presentation discusses the impact of tap cleaning on the microbiological situation for the tap itself and for the whole dispensing system. In other words - is tap care worth the effort?
Materials and methods for data collection: Practical investigations have been carried out with the following experimental design: A test rig consisting of five beer lines identical in length, diameter, construction and mountings was used. All the beer lines were equipped with the same tap design. In cases of tap care a tap-ball was deployed. One series of tests ran for six weeks and was repeated three times to meet statistical requirements. Concerning the tap care five different parameters were determined:
Tap 1, treated daily with water;
Tap 2, treated daily with disinfectant;
Tap 3, treated with disinfectant once a week after line cleaning;
Tap 4, no tap treatment after line cleaning.
The total equipment was cleaned chemically on a weekly basis. As a control, Tap 5 was used without a regular cleaning interval to demonstrate the prompt contamination without a regular treatment. Once a week two samples from each line were taken and tested for microbial load by plate count.
Results: The first sample indicated the microbiological situation at the tap and the following sample represented the beer line behind the tap or rather the situation of the dispensing system.
Discussion: In comparison to the standard weekly cleaning procedure with tap treatment, the microbiological load due to daily treatment could be reduced dramatically as early as three weeks.

What is new - Daily cleaning of the tap with water or disinfectant showed a significant reduction of the microbiological load at the tap and - which is very interesting - also in the beer line behind the tap. In summary it has to be concluded that tap care improves the whole microbiological situation of a beer dispensing system considerably and gives all outlets with high quality standard a competitive advantage in selling draft beer.

 

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Description of topic: The balance and harmony of the beverage matrix seems to be the basis of good Drinkability, therewith mouthfeel and body of a beverage. Mouthfeel is a product’s physical and chemical interaction in the mouth. The term is used in many areas related to the testing and evaluating of foodstuffs (beer-tasting, non- alcoholic beverages, rheology). By the sensory evaluation of beer the impressions of beer´s smell, taste, body, carbonisation taste and bitterness were evaluated mostly in a score system from 1 to 5. The importance of beer-tasters achieving a common understanding of terms describing beers mouthfeel is important. For this reason the beer industry has a standardised terminology wheel of mouthfeel and taste terms, but nevertheless the description and characterisation of the attributes body, mouthfeel or smoothness in sensory evaluation is mostly not very specific.
Materials and methods for data collection: In this project specific reference substances were selected which are accompanied with different impressions of body and mouthfeel. The attributes were collected and together with a human taste panel a procedural method for a panel training exclusive on the attributes body and mouthfeel were developed. A human taste panel is trained to describe their sensations with standardised terminology and a uniform developed taste schema.
Results: The elaboration of terms and concepts for panel training with regard to the attributes body and mouthfeel is described.
The successes of panel training and the practicability of the taste schema were checked in different matrix compositions.
Discussion: It is common practice by sensory quality control and commonly used taste tests to evaluate - beside smell, taste and bitterness - the body of a beverage, especially in the brewing industry. Nevertheless also well trained panel participants have problems with the description of body and mouthfeel.
One reason is, that no specific panel training with adequate reference substances is available.

What is new - Up to now exists no generally accepted tasting schema for the attributes body and mouthfeel. Further no reference substance for a panel training or a training procedure are available. But training for a good capacity for remembering is required. In this project a human taste panel worked out suitable reference substances for body and mouthfeel impression. These reference substances were assigned to a standardised terminology. A concept for a panel training and a specific schema were developed.

 

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Description of topic: The Italian beer market is dominated by bottom fermented lager beers which have 97% market share. Sensory descriptions of beer are usually self-highlighted by producers, and beer descriptions are most of the time subjective in nature and biased by the effort to catch consumers’ attention and favour marketing purposes. Sensory profiling techniques in turn are effective in objectifying these descriptions. This study extensively investigated the sensory profile of lagers of the Italian market to map out its structures. Then it explored the chemico-physical properties and the flavour active compounds generated during fermentation of a subset of 10 samples chosen on the base of their market share. Flavour compounds included higher alcohols, short-chain fatty acids and esters. These compounds are usually present in trace and in lagers with a % ABV from 4 to 5.5 they seldom reach their threshold level, most of the time reaching levels around the threshold value. However they can affect the flavour profile due to a synergistic effect on individual flavour.
Materials and methods for data collection: Descriptive sensory profiles of 27 lagers were determined using: a) a trained panel and an established language (Meilgaard et al., 1979); b) a 9-point Likert like scale anchored at both ends. A subset of 10 samples was selected for exploring the chemio-physical properties and the flavour active compounds (FAC) derived from the fermentation process. FAC were measured by GC (Silva et al.,1988). One-way Anova and Tukey HSD test determined statistically significant differences among beers. Factorial analysis and biplots were used to visualize the results.
Results: Lagers were discriminated (P<0.05) with sensory profile techniques. Cardboard-like, metallic and estery flavours were the most discriminating descriptors. Likewise flavour active compounds discriminated (P<0.05) our samples. Relationships between sensory and analytical data were mixed.
Discussion: Although lagers tend to have similar flavour a wide vertical differentiation was observed.

What is new - This is the first time that in lagers from the Italian market: a) the flavour profile was extensively studied: b) the most common fermentative aroma compounds were explored; c) the relationships between compositional and sensory data were explored. This study has practical implications for brewers who wish to introduce or reposition a new or existing brand into the Italian market. Correlations between sensory profiles and brand market share and/or consumers’ preference can be easily traced.

 

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Description of topic: The noticeable beer flavour is the result of complex interactions of different aroma compounds. On one side there are pleasant flavour impressions from hops and desired fermentation by products. On the other hand Off-flavours (stale flavours, diacetyl, DMS) can be present in beer and result in an undesired flavour. Esters produce a fruity flavour which can mask other flavours. Another positive flavour compound is the hop derived linalool. It is known to be a good indicator and main contributor to the hoppy flower-like flavour. Beers with a hoppy flavour show a better flavour stability.
Materials and methods for data collection: To investigate the interactive effects of different flavour compounds we used the EBC method 13.9 for taste threshold determination. We compared the thresholds of single compounds with mixtures in commercial beer.
Results: Additive flavour effects are a widespread phenomenon and have been reported repeatedly. The threshold of some stale flavour compounds if combined can be 80 % lower than that of single substances in beer. We tested typical stale flavour compounds like 2- and 3- methylbutanal, gamma-nonalactone and others pure and in combination with chemical similar stale flavours. There was an increase in intensity of the combinations compared to the single compounds. Beside the stale flavours some hop volatile compounds, like geraniol, linalool, beta-caryophyllene, were in the focus of our experiments. They were tested single and combined with other hop compounds as well as 2-phenylethanol. Because of the huge chemical diversity of the hop compounds additive effects could not be observed between the hop compounds in the same extend as between stale flavours. We also tested the influence of esters on the threshold of diacetyl, DMS and 3-methylbutanoic acid. The positive esters masked the negative off-flavours.
Discussion: These results show that the influence of interactive flavour effects should be considered in the sensory evaluation of beers and in sensory training.

What is new - Interactive effects of complex mixtures are well known but they have not been investigated for beer. We analyzed these effects for desired flavour compounds (esters) and off-flavours as well as additive effects of stale flavours and hop volatile compounds. It is shown that the impact of these interactive effects has an important influence on the resulting beer flavour.

 

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Description of topic: Although it is long known that the typical bitterness of fresh beer is mainly imparted by the cis/trans-iso-a-acids, the bitter taste induced by these compounds is not stable and a significant decrease in intensity as well as a change in bitter quality is observed with increasing age of the beverage. Various studies showed evidence that the amount of trans-iso-a-acids in beer decreases during aging, whereas the cis-iso-a-acids seem to be rather stable. As scientific data on this degradation are lacking, the objective of the present study was to elucidate the mechanisms involved in storage-induced iso-a-acid degradation and formation of unpleasant and harsh bitter compounds in aged beer.
Materials and methods for data collection: Isolation, NMR, LC/MS, sensory
Results: Aqueous solutions of purified trans-iso-a-acids were incubated, the reaction products formed were isolated, and their structures determined by means of NMR and LC-MS. Based on the chemical structures of these previously unknown degradation products and guided by stable isotope labelling experiments, a novel conclusive reaction pathway was proposed explaining why and how the trans-a-acids are degraded via a non-oxidative mechanism, whereas the cis-iso-a-acids stay rather stable during beer storage. By means of HPLC-MS/MS, all previously unknown compounds were identified and quantified in various beers and were demonstrated as the predominant degradation products accounting for almost 100% of the loss of trans-iso-a-acids in aged beer. Furthermore, sensory studies revealed a change of bitter quality for some degradation products as well as somewhat higher bitter recognition thresholds when compared to the data obtained for the trans-iso-a-acids.
Discussion: On the basis of dose/activity considerations, it could be demonstrated for the first time that the generation of the trans-iso-a-acid degradation products is responsible for the slight bitterness decrease as well as the change to a more harsh and lingering bitter quality during long-term storage of beer.

What is new - For the first time, the degradation products of trans-iso-a-acids were identified, their bitter taste properties characterized, as well as the pathways leading to their formation upon storage of beer elucidated. All these unknown compounds were quantified in beers and found as the predominant aging indicators accounting for almost 100% of the loss of trans-iso-a-acids in stored beer. These molecules are responsible for the change in bitter intensity and quality during beer storage.

 

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Description of topic: Dark specialty malts can have a tremendous impact, not only on flavour and colour but also on beer flavour stability. The influence of these malts on the latter generates contradictory evidence. Therefore, reducing power assays were combined with a sensory and analytical approach to investigate the influence of different types of specialty malts on flavour stability.
Materials and methods for data collection: Two 20 EBC amber beers, made with caramel-colour malt, were brewed in duplicate in a 5hl pilot scale brewery. Identical processing parameters were applied. The beers were thermally aged at 40°C. The reducing power was assayed with DPPH and Fe-dipyridyl. Sensory analysis was performed by a trained panel. Staling flavours were analysed by SPME-GC/MS and H-GC. Furanones and pyranones were extracted with diethylether and analysed with direct injection GC/MS.
Results: DPPH and Fe-dipyridyl values remained constant during ageing in the colour malt beer. The severe drop in reducing power of caramel malt beer was accompanied by a spectacular decrease of sensory appreciation. However, the fresh and aged beer still scored significantly higher during sensory analysis than its colour malt counterpart. Staling compounds such as the Strecker aldehydes, furfural, HMF and lipid oxidation products were more abundant in aged colour malt beer. By contrast, furfurylethylether was higher in the caramel malt beer. The evolution of maltol and furaneol was monitored to explain the drop of caramel notes in aged caramel malt beer.
Discussion: The redox capacity of caramel malt beer drops during ageing contrary to colour malt beer. In addition, sensory analysis proved that caramel notes are lost during ageing in caramel malt beer. Components such as furaneol and maltol can act as antioxidant and have a caramel flavour due to their molecular structure. When these components are oxidised, the structure and consequently the flavour is lost

What is new - This research combines reducing power, analytical and sensory techniques to unravel the impact of specialty malts on beer flavour stability.

 

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Description of topic: The research aimed to investigate the influence and improvement of flavour stability of pale lager beer products by using ten selected colouring agents such as specialty malts, beer colour extract and artificial caramel colorant. Likewise, it was determined whether the adjustment of colour by using the colouring agents mentioned could be a relevant tool for improving the beer flavour stability; either by means of chemical effects or by psychophysical responses as colour appearance.
Materials and methods for data collection: Ten pale lager beers were brewed at the pilot brewery of the I.C.B.D. using different colouring agents, including: specialty malts, roasted barley, beer colour extract and artificial caramel colorant for colour adjustment. The influence of the final colour appearance on the flavour stability of the produced beers was examined. The colour intensity of the beers was analysed by the EBC methods. The colour appearance was evaluated by sensory viewing and predicted by tele-spectroradiometry and digital imaging methods according to the CIECAM02 model. The flavour stability of the beer samples was measured by quantifying beer ageing compounds using PFBOA fibre and analysed by GC-MS in SIM mode.
Results: The colour appearance attributes (lightness, colourfulness, hue, opacity and clarity) of the locally-brewed beers either by psychophysical assessment or physical measurements did not match with the corresponding EBC values. This may indicate EBC method does not allow understanding the true colour perception of the beers by the consumers. Likewise, it was found that apparently using a specific group of specialty malts for colour adjustment can improve the beer flavour stability.
Discussion: According to the results obtained, it is necessary to establish and to perform uniform brewing practices by the brewer as well as to apply new technology and measurements procedures in order to obtain consistent product in terms of beer colour appearance and flavour stability.

What is new - The research could evoke sustainable and commercial benefits: for instance upgrading of materials by initial processing, optimisation of material yield and inventory management. Likewise, a significant contribution can be carried out for the production of more consistent pale lager beer products in terms of world-class market and enhanced flexibility in terms of logistics and planning.

 

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Description of topic: This paper describes the validation of a new method for measuring drinkability without asking consumers to drink large volumes of beer. The technique measures changes in consumer liking and those factors which influence the desire to stay with or swap to another beer or different drink. A consumer study completed in July 2008 was successful in demonstrating significant differences in the drinkability of two beers and provided detailed information on factors influencing consumer liking.
Materials and methods for data collection: Data was collected from 124 consumers from two UK locations, with a 49:51 male:female gender split. Two commercial beers were used in this study and consumers drank up to 4/5 small glasses of each beer and completed a questionnaire after each glass.
Results: Using this method we were able to show that the technique was successful in measuring differences in the drinkability of the two beers. Analysis of the consumer data showed that there were significant differences in overall liking and flavour between the beers. The method demonstrated that there were significant differences in ratings between glasses of the same beer and in responses due to gender. The technique highlighted which sensory attributes were related to consumer liking. Using the method, we could identify factors which affected the desire to continue drinking a beer or prompted a desire to change to another beer or different drink. In-depth analysis of the data identified a target group which would be useful as a marketing strategy for this brand.
Discussion: No brewing company nowadays can afford to be without some means of measuring the drinkability of their beers. With the current Government concerns over irresponsible and excessive drinking, the Brewing Industry is under pressure to promote moderate drinking. The validation of this new method allows changes in consumer taste preferences during the moderate consumption of a beer to be measured.

What is new - This method investigates both consumer liking and how consumer perception changes with the volume of beer consumed. These changes can lead to the continued consumption of the beer or brand switching. The study validates a new method for measuring drinkability as a way of assessing a key sales parameter without upsetting public morals. The technique can also explore reasons why consumers switch beer brands during a drinking session and what it is about the beer which triggers preference change.

 

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Description of topic: Oxidative processes with radicals as important intermediates have a significant impact on the quality and stability (shelf life) of beer. The oxidative reactions in beer are well studied, whereas the extent and impact of oxidative reactions, occurring during early stages of brewing, are not fully explored. Mashing has been identified as a critical step of oxidative events during the beer production, which is likely due to the lack of reducing power to quench reactive radicals such as the hydroxyl radical formed by the Fenton reaction:
Fe2+ + H2O2 -> Fe3+ + •OH + OH-
H2O2 is thus an important intermediate of the oxidative processes initiated during mashing.
Materials and methods for data collection: This paper will describe how a thermostable catalase (EC 1.11.1.6), applied as a regular mashing enzyme, can improve the oxidative stability of wort, by efficient removal of H2O2, which leads to improved beer flavour stability. The Electron Spin resonance (ESR) based method, which has become a well established tool for evaluating the flavour stability of beer in many major breweries, were used to examine the effect of a thermostable catalase on the oxidative stability of the resulting wort and beer.
Results: In a laboratory scale mashing system, catalase treatment demonstrated a significant decrease of the initial rates of radical formation (p<0.05) of wort, accounting for a 20% reduction. In lager beer pilot scale trials at VLB, Berlin, catalase significantly improved the endogenous antioxidative potential (EAP) and reduced the amount of radicals formed in the resulting beer. Consistently, catalase treatment during mashing resulted in a significantly improved beer flavour stability as evaluated by a professionally trained sensory panel.
Discussion: This paper will discuss how a novel and thermostabilised catalase enzyme, applied during mashing, can improve the oxidative stability of wort, by efficient removal of hydrogen peroxide, which leads to improved beer flavour stability.

What is new -

 

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Description of topic

There are two fundamental chemical pathways involved in beer staling, namely:

1. the oxidation of fatty acids and their derivatives and
2. the Maillard reaction.

Both pathways are characterized each by a specific set of stale flavour descriptors attributed to them. While pathway a) is considered as being linked to rancid, papery or cardboard notes, reaction scheme b) is regarded as the origin of burnt, caramel- and bread-like notes. The relative importance of the two stale flavour types is assessed by examining aroma characteristics of force-aged industrial beer samples.

 

Materials and methods for data collection

Flavour stability characteristics have been assessed by an expert taste panel.

 

Results

Force-aged industrial beer samples have been examined over a period of almost four years and their flavour characteristics compared. In a general overview of all beers studied, no clear tendencies become visible. However, although most beers show a blend of flavour characteristics attributable to both pathways, some can be characterized predominantly by the descriptors belonging to only one of the two reaction schemes. More detailed studies reveal that hopping with conventional products versus light-stable (reduced) isohumulone extracts marks a difference in the type of stale flavour which emerges during forced ageing. In our experience, conventionally hopped beers tended to show mostly cardboard and similar flavours linked to pathway a) while so-called light-stable beers hopped with reduced isohumulone extracts gave primarily burnt, bread- and caramel-like stale flavours attributable to scheme b).

 

Discussion

Research about the oxidation of fatty acids dates back many decades. Already in the 1970s, the general principles of the pathways involved were known (1, 2). In contrast to that, the importance of the Maillard reaction for beer staling was not the prime focus until only a few years ago, when data was published concerning the link between this reaction and burnt, bread- and caramel-like flavours in beer (3). As a matter of fact the terms “stale”, “oxidized” and the like are not sufficient to characterize the flavour of beer after ageing. A multitude of descriptors has been developed and most can be traced back to the two major chemical pathways of beer staling mentioned above. This study revealed that there is a close correlation between the type of stale flavour detected (a or b) and the type of beer, either made with light-stable or with conventional hopping. These statistical findings match with earlier reports on similar topics (4, 5).

 

What is new?

The importance of the two major chemical pathways involved in beer staling is reviewed, examined and compared.

 

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Description of topic: A part of the quality parameters of barley is determined by the genetic disposition of the raw material. This means that besides environmental conditions the barley variety is responsible for a large part of the processability. During the parallel development of processing technology and quality potential of barley varieties, plant breeding represents the major part.
Materials and methods for data collection: At the LfL field trials with barley varieties are documented since 1907. The results of official variety trials in Germany and Bavaria over many years were statistically analysed to demonstrate the long term progress in malting quality.
Comparative field trials performed in the context of the research project GABI MALT consisting of 42 diverse spring barley varieties registered between 1951 and 2002 were grown in four environments to achieve an unbiased comparison of the traits.
Results: Results of official variety trials confirm the improvement of all important quality parameters by plant breeding.
Results of comparative field trials in the context of GABI MALT show uniquely how quality and processability of barley was improved. During this time all important parameters were adapted to the needs of the processing industry. Malt extract could be increased by two percent. Friabilimeter grew from 70% to over 90%, Kolbach index was increased from 37% to 45%. The major part of this improvement is due to the efforts of plant breeding. Increased extract yield, improved cytolytic and proteolytic performance of the malt result in optimal supply of yeast with nutrients, optimisation of the duration of attenuation, maintenance of foam and taste stability and improvement of the usage time of the filters.
Discussion: The sum of all these improved traits means a clear economic advantage for the brewing industry.
Improvement of quality means also a slower increase of yield. The perspective for the improvement of barley quality is the optimal combination of particular parameters or genes by application of molecular marker technology.

What is new - Evaluation of field data from 40 years;
Comparison of old varieties registered from 1951 to 2002 in a standardised environment and malting;
Transfer of the improvement of barley quality to the economic advantages in processing;
Perspective of quality improvement by breeding using novel technologies;
Demonstration of the importance and necessity of plant breeding to meet future demands of maltsters and brewers

 

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Description of topic: 4-vinylguaiacol (4VG) is known to be an essential contributor to the aroma of many top-fermented beers (especially German and Belgian wheat beers). In this study, we identify critical control points to optimize its concentration in beer. Secondly, since already several authors reported appreciable temperature dependent losses of 4VG during the storage of beer leading to a steady decline of the phenolic flavor impression, we examined its degradation patterns during beer ageing.
Materials and methods for data collection: Experiments were conducted in a pilot brewery (5hL). 4VG was analyzed by HPLC-ECD. Degradation products of 4VG were analyzed by SPME-GC-MS and direct injection GC-MS. Other important flavor compounds were monitored by Headspace GC-FID.
Results: The effect of the yeast strain, temperature, pH, pitching rate and initial precursor level were investigated. Clearly, the first means for optimizing the final content in beer is by controlling the release of precursors in the brewhouse and the choice of a suitable yeast strain. It was also shown that current practices like top-cropping and applying counter-pressure, can severely affect 4VG formation and may affect the ratio between 4VG and esters leading to an unbalanced beer. Finally, the decrease of 4VG during beer ageing was examined. A new vanilla-like compound in beer, apocynol, was identified as the main degradation product. In the presence of oxygen, substantial amounts of vanillin were also detected.
Discussion: A careful control of fermentation parameters is crucial for optimizing the final level of 4VG in beer. Pilot-scale experiments showed that modern yeast management systems frequently encountered with cylindroconical tank fermentations significantly affect 4VG formation. During beer ageing, two reaction mechanisms leading to the decrease of 4VG were identified. The decrease of 4-vinylguaiacol during beer ageing may impart a shift from a clove-like aroma in fresh specialty beers to a more sweet, vanilla-like flavor impression of aged specialty beers.

What is new - While the origin of 4VG in beer basically is known, not many means are known for the present day brewer to optimize them in the final beer. In this study, we identify critical control points to optimize their concentration in beer. Also, the evolution of 4-vinylguaiacol during beer ageing was investigated and the products, which arise from it, were identified for the first time. Two reaction mechanisms leading to the decrease of 4-vinylguaiacol during beer ageing were found.

 

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Description of topic: The properties of the iso-alpha-acids mean that these compounds are able to support beer foam, elicit bitterness and act as potent antimicrobials against Gram-positive bacteria. In this paper, we review the state-of-the art for each of these quality issues, emphasising recent developments in areas such as the identification of the so-called T2R bitterness receptors, and the application of molecular dynamics for the exploration of hop acid-protein binding.
Materials and methods for data collection: This paper is a state-of-the-art review of developments in a range of scientific disciplines that are relevant to the behaviour and performance of the iso-alpha-acids and their reduced counterparts. The focus here will be on the recent observations regarding the T2R bitterness receptors (and contrasting these with the T1R sweetness receptors) and the use of molecular modelling and simulation studies to elucidate the interaction between proteins and hop acids.
Results: Around 40 T2R (bitterness) receptors have been tentatively identified. This variation can help to explain why there is so much structural diversity of bitter compounds. These G-protein coupled receptors bind bitter compounds to the outside of the receptor which triggers a cascade ultimately resulting in bitterness perception. There is still the possibility that the ability of hop acids to partition into lipid bilayer membranes might enable them to by-pass the T2R receptors and interact directly with receptor cells. Molecular dynamics simulations have clearly demonstrated that hop acids not only associate with proteins, but also with themselves.
Discussion: The iso-alpha-acids exist in a range of isomeric forms. Molecular modelling indicates that the ratios of these forms varies between the cis- and trans-forms, which may explain small differences in their properties. Experimental observations indicate that hop acids have an affinity for hydrophobic regions on proteins, which has now been simulated using molecular dynamics techniques.

What is new - Scientific developments in fields outside of the brewing science arena can be utilised to enhance beer quality control and to rationalise experimental observations. In particular, the use of molecular modelling to rationalise previous experimental observations made and the characterisation of bitterness receptors which are now succumbing to protein-ligand binding studies offer the opportunity for brewers to both understand, and to exploit this new knowledge for the benefit of their brands.

 

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Description of topic: Fusel alcohols and the esters derived therefrom are important flavour and aroma constituents in beers. Consistent batch-to-batch maintenance of the desired concentrations of these compounds is essential. The aims have been (1) to define the steps of the biochemical pathway (the ‘Ehrlich pathway’), (2) to identify the enzymes involved and the genes which encode them, and (3) to understand the biochemical and genetic regulation associated with changes in yeast’s growth and environmental conditions.
Materials and methods for data collection: The methods included the use of amino acids specifically labelled with 13C followed by 13C NMR spectroscopy to identify the metabolic sequences, specific mutants suspected or known to encode particular enzymes/isoenzymes, overexpression of structural genes and transcriptome profiling.
Results: Leucine, isoleucine, valine, phenylalanine, tyrosine, tryptophan and methionine that are present in wort serve as the starting materials for the formation of isoamyl alcohol, ‘active’ amyl alcohol, isobutanol, 2-phenylethanol, tyrosol, tryptophol and methionol (respectively). The steps of the Ehrlich pathway are transamination in which the amino acid is converted into an alpha-keto acid, then decarboxylation in which the alpha-keto acid is converted to an aldehyde. The aldehyde is then reduced in a NADH-linked reaction resulting in formation of the appropriate fusel alcohol. In aerobic conditions (not found in beer production), the aldehyde could be oxidized to the corresponding fusel acid. Four transaminases, 5 TPP-dependent decarboxylases, 16 alcohol dehydrogenases and 8 aldehyde dehydrogenases have roles in the pathway depending mainly upon the amino acid, growth phase of the yeast and other cultivation conditions. Transcriptional regulation of the structural genes explains most, but not all of the regulation observed. Posttranslational modification(s) of enzymes remain to be discovered.
Discussion: Recent work has led to a far more complete understanding of fusel alcohol formation and its regulation.

What is new - The development of elite strains dedicated to specific processes and with greatly-improved consistency of performance is a realistic possibility.

 

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Description of topic: Lactic acid bacteria (LAB) have been recognized as major spoilage microorganisms in the brewing industry. These spoilage LAB exhibit strong hop resistance and grow in beer, a harsh environment where ordinary LAB cannot survive. It has been also known that beer-spoilage LAB strains are rare in nature and almost exclusively isolated from brewery environments. However, questions remained in a state of mystery as to how these spoilage LAB have emerged in the brewing history and acquired beer-spoilage ability in the evolution of these bacteria.
Materials and methods for data collection: x
Results: Recent studies increasingly suggest that beer-spoilage LAB emerged as brewers began the cultivation of hop for brewing. Since then, beer-spoilage LAB presumably chose brewing environments for their habitats, and progressively developed intricately complex mechanisms to survive in beer. Therefore, the adaptation of beer-spoilage LAB to beer environments appears to be quite a long process, which most likely can be traced back over a thousand years. Strikingly, deep association of spoilage LAB with beer environments led to the acquisitions of hard-to-cultivate characteristics on ordinary culture media and the accumulation of common resistance genes among different species of beer-spoilage LAB. These phenomena are significantly relevant for micro quality control (QC) tests in breweries, such as detection and identification of beer-spoilage LAB.
Discussion: Intriguingly, spoilage LAB in other alcoholic beverages seem to have followed similar paths in their own evolution and emerged as spoilage microorganisms. In fact, these spoilage LAB went through complex adaptive processes unique to respective alcoholic beverages and became deeply associated with their own environments. The ways these spoilage LAB share common biochemical and genetic phenotypes are beyond their species status. In this review, the origin of beer-spoilage LAB and its implications in micro QC in breweries will be discussed in relation to other spoilage LAB in wine, cider and sake.

What is new - Although this is a review of existing literature, there are a lot of new insights into common features shared by spoilage LAB in various alcoholic beverages, which have been previously unexplored. The common denominators of these spoilage LAB are the profound adaptation to harsh environments that only allow few microorganisms to survive. Indeed, these spoilage LAB chose incredibly similar paths to become deeply associated with their respective habitats, which goes beyond speciation processes.

 

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Description of topic: The majority of the world’s major international beer brands are produced via high gravity fermentations performed in large capacity cylindroconical fermenters. In order to maximize productivity large batch sizes, high wort concentration and elevated temperatures are used. This exposes yeast to hostile conditions. It is relatively common to encounter a lack of balance between brewhouse and fermentation and protracted fermenter fill times are common. This requires decisions as to when and at what rate should pitching and oxygenation be made. Typically these decisions are empirical. At previous EBC congresses it has shown that management of fermentation can result in heterogeneities that persist throughout most of fermentation. The conclusions that may be drawn from these factors are that precise regulation of parameters such as pitching rate, temperature and oxygenation are not sufficient to ensure predictable fermentation performance, high crop viability and consistent beer quality. Here a review is presented of current best practice of the control of fundamental fermentation control parameters. This is extended to discuss how these fermentation variables can be manipulated to provide a predictable outcome. Results are presented which illustrate the problems that may be encountered with some current control regimes together with those where ameliorative actions have been put into place. A simplified fermenter design is presented which seeks to address some of the problems described here.
Materials and methods for data collection: Data was collected from production records and trials performed at laboratory and pilot scale.
Results: The results of fermentations performed at several commercial breweries are presented.
Discussion: The intention of this presentation is to spark a debate where the motion will be that current fermenter design may be not be entirely suited to modern needs. A new model is presented together with guidelines for management which seek to redress some of the problems that have been highlighted.

What is new - A new and simplified design of large capacity fermenter is presented together with a proposed method of management which is suitable for high gravity fermentation and which will safeguard yeast quality whilst providing consistent performance.

 

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Currently a lot of EU legislation is being developed or revised under the umbrella of the Sustainable Consumption and Production (SCP) Action Plan and the EU Action Plan for Energy Efficiency. Examples of proposed measures are Ecolabel Regulation and the Ecodesign Directive being part of SCP Action Plan. The CO2 Emission Trading Scheme is an instrument to reduce emissions under the Action Plan for Energy Efficiency. Other relevant legislation is the recast of the Integrated Pollution and Prevention Directive (IPPC), the recently adopted Waste Framework Directive (WFD) with the 5 step waste hierarchy and the REACH Regulation (Registration, Evaluation Assessment and Restriction of Chemicals).

The Brewers of Europe are following developments in this area in order to protect the interests of the brewers. The Issue Management Team (IMT) Environment of the Brewers of Europe works together with the CIAA (Confederation of Food and Drink Industries in Europe), especially by participation in the Environmental Committee of the CIAA. The presentation deals with several issues that have been or are on the agenda.

For the future, it is important to stay involved in the legislative processes in Brussels. It is also important to realize that the brewers are part of the supply chain from farmer to consumer. Cooperation with all actors in the chain is important to enable further environmental improvements.

 

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Description of topic: Often brewing facilities that were once planned and built on the outskirts of a city have over the years become surrounded by residential buildings. Very often, odour emissions from wort boiling are perceived as unpleasant by many residents, particularly if vapours are emitted through the vapour stack throughout the whole year. When residents are then complaining, the brewery must take action and has to find a remedy.
So far, most measures for the reduction of odour emissions have required extensive upgrades and high maintenance efforts. The aim was to find a simple and cost- effective method for lowering the odour emissions from brewhouse vapours.
Materials and methods for data collection: A joint project of Vereinsbrauerei Apolda, company Luwatec and Huppmann investigated a new method that oxidizes and neutralizes vapour emissions. An ionisation system was installed behind the vapour condenser of the wort kettle in the Vereinsbrauerei Apolda. The vapour condenser itself has two equal vapour stacks. To determine the degree of odour removal achieved by such an ionization system, an olfactometric analysis of the brewhouse vapours and a measurement of the TOC (total organic carbon) values have been carried out by the German TÜV.
Results: With the installation of an ionization system at Vereinsbrauerei Apolda, the original intensity of odour emissions from wort boiling could be reduced by at least 70 %. This was confirmed by a TÜV report.
Since the installation of the ionization system, the brewery has not received any more odour nuisance complaints from residents.
Discussion: With its low energy consumption of only 1.5 kW, fully automatic operation and less maintenance requirements, the ionization system in the Vereinsbrauerei Apolda could meet the objective to find a simple and cost-effective solution to reduce odour emissions from brewhouse vapours.

What is new - The ionisation system clearly reduces odour emissions from brewhouse vapours similar to those conditions found in nature. Flavour-active hydrocarbons will be transformed into carbon dioxide and water by oxidation reactions under the presence of activated oxygen. This process is well known as "cold combustion" which also results in the “clean air” impression after heavy rain falls in combination with thunderstorms. In comparison to other systems the operational costs are very low.

 

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Description of topic: The price development of fossil fuel has a huge impact on the opinion-making process in the brewing industry regarding the use of renewable energy sources.
It is important that breweries are increasingly considering the use of spent grains or other energy rich waste of breweries to replace fossil fuel.
Materials and methods for data collection: The energy content of partially dried spent grains is comparable to that of wood or regular brown coal.
Spent grains combustion in the brewing industry has a short history and only two systems with forward acting reciprocating grate are at present installed. Huppmann decided to investigate the best condition for spent grains combustion in cooperation with Fraunhofer Institute, a privately funded research institute.
To evaluate the best conditions for spent grains combustion the trials have been made in a pilot plant, followed by trials in an industrial installation.
Results: The applied combustion box technique can be used for burning the spent grains of lauter tuns and mash filters. Even the combustion of DDGS, the by-product of bio-ethanol production, is possible without major changes in technique or applied process parameters. In addition other waste like yeast can be burned together with spent grains. Used labels of the bottle cleaning machine or the sludge of the waste water treatment plant should be considered as alternative fuel.
The results showed that standard exhaust gas cleaning systems with flue gas recirculation, electric filters and bag filters are sufficient.
The technique of the combustion box and the applied process technology allow, that emissions of CO, NOx, HCl and SO2 could be kept within the requested limits of the German Technical Instructions on Air Quality Control.
Discussion: The designed fluid bed combustion can burn the energy rich waste together with spent grains or in combination with wood chips. This system enables the brewer to generate steam or hot water with biomass and brewery waste and the brewery is able to substitute all fossil fuels.

What is new - Huppmann has designed a specific system for the combustion of spent grains, DDGS and/or wood chips. Other waste like waste water treatment sludge, washed off labels or discharged yeast can be fired in the fluid bed combustion too. The combustion box works in combination with partial mechanical dewatering of spent grains and an adapted boiler system, in accordance with the requirements of breweries.

 

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Description of topic: Creating a climate strategy may challenge your company much more than energy efficiency programmes ever did, although they are naturally linked. What are the main differences between energy efficiency and climate strategy? What are the financial costs and benefits of a climate strategy? How du you set up realistic targets and implement them in your climate strategy? These are some of the questions which will be answered in this presentation. Industry can reduce CO2 emissions by means of strategic climate investments and/or energy efficiency projects. You will get an overview of the challenges and benefits involved with both alternatives, and learn how they can work together. A look into economics will present the cash flow impact involved with various initiatives relating to energy. Performance measurements are important but you will be questioned whether KPI´s are sufficient measures?
Materials and methods for data collection: The presentation is based on the Danfoss company case. Data collection also includes benchmarking, and advising companies when they prepare their climate strategy.
Results: Understanding the difference between climate strategy and energy efficiency, and economics thereof. Learning how energy efficiency programmes can support or even finance a climate strategy. Knowing which challenges will be part of this. Knowing why the most cost-effective CO2 reduction initiative is to reduce utility consumption at industrial plants.
Discussion: Climate policy is a challenge and an opportunity. What are the challenges for our business and industry in connection with climate strategy building? Commitment to a climate strategy involves moving away from mere energy efficiency measurements and energy efficiency targets. Is it a must?

What is new - The potentially dramatic difference between climate strategy and energy efficiency.

 

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Description of topic: Mash filters are gaining importance in the technology of wort separation with growing brewhouse capacities and unit sizes. In proven technology which has been in place for several decades the unit size was limited to approximately 12 tons of grist charge for many years. High gravity brewing, faster turnaround times and higher utilisation of brewing lines made it necessary to develop mash filter units of larger size. The new generation size of mash filters is beyond 26 tons of grist. They are now in operation for several years. The paper shows new construction details and the differences as well as and process performance compared to previous constructions. Several details lead to improved technical performance. Technologically the new filter generation gives very good results in yield, occupation time and overall capacity. The wort quality compares very well with previous systems. The paper describes technical improvements supported by technological effects. The central rail support system allows fast mechanical movements and a smooth and even mash transfer and distribution. Efficiency provides yields above laboratory values, while solids are low in general accompanied by good turbidity. All quality parameters were measured during commissioning of new full size filters equipped with this technique. . Within selected brewhouse designs, the unit is quite flexible regarding the variation of raw material quality.
Materials and methods for data collection: The reference plants for this investigation are located in Mexico, Russia and Asia. The capacity of plants is > 26 tons of grist, reaching capacities of 14 batches per day
Results: The results were taken from practical large scale industrial brewhouse installations. The analyses were done by TUM.
Discussion: Good technological results are available from large filter units at high capacities up to14-16 brews/24h. Average yield figures are very close to general brewhouse specifications according to MEBAK. Most interesting is the ability to use different qualities of raw materials.

What is new - The new generation of mash filters now provides proven technological results which indicate high quality of wort in relation to varying raw material quality.

 

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Description of topic: At the EBC congress in Venice (2007), Aerts presented a new approach of wort production. Classic boiling might be eliminated. Fine milling, mashing-in conditions whereby oxidative reactions are blocked, mashing-off at 95°C to improve an early protein/polyphenol flocculation and degradation of pDMS, can deliver a wort with a high stripping need without boiling need. In this lecture the concentrations of pDMS, DMS, DMSO and aldehydes during innovative wort production are compared with classic brewing.
Materials and methods for data collection: Brewing experiments (5hl-12°P): (wet disc mill) fine milling under water; mashing-in at 65°C, pH 5.2; mashing-off at 78°C/1 min (1) or 95°C/15 min (2). Thin bed filtration at 78°C (1) or at 85°C (2) . One hour boiling in case of mashing-off at 78°C; in-line heating and stripping in case of mashing-off at 95°C. No extra boiling time was performed. Hot wort clarification in decanter (combination vessel).
pDMS, DMS, and DMSO was measured by HS-SPME-GC-PFPD. Aldehyde profiles were determined by HS-SPME-GC-MS.
Results: Classic brewing under the mentioned conditions delivers already a wort with low amounts of aldehydes. pDMS degradation is according to literature. Total process time was 6 hours.
Innovative produced wort had comparable aldehyde profiles. Also the free DMS concentration was very small. Residual amounts of pDMS in pitching wort was slightly lower and the DMSO content is comparable with classic anti-oxidative brewing. Total process time for innovative brewing was 4.5 hours.
Discussion: Despite of fine milling, de novo formation of aldehydes was prevented. In case of innovative wort production, pDMS degradation starts at mashing-off prior to wort filtration and DMS is stripped off before entering the combination vessel. The temperature of the wort during kettle filling remains above 99°C to continue pDMS degradation and DMS removal by efficient stripping. Total production time is decreased by 25% and energy use is lower due to efficient heating with clean steam injection.

What is new - Innovative wort production under the presented conditions delivers a pitching wort with low amounts of unwanted volatiles. Total process time is decreased as well as the energy consumption. The low heat load will result in low carbonyl potential of wort and a higher assimilability of FAN during fermentation. An improved flavour stability of the beer is therefore expected.
The combination of a more economic process with a better wort profile is unique in the beverage industry.

 

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Description of topic: Previous studies demonstrated that proline-specific endo protease (PSEP), commercial name Brewers Clarexä, enables brewers to efficiently stabilize beer by specifically hydrolyzing haze active proteins thereby preventing complex formation with polyphenols. Here, new results demonstrate that PSEP also enables maturation capacity increase, energy costs reduction and lower carbon footprint while maintaining beer quality.
Materials and methods for data collection: Semi-industrial trials were performed at two international institutes (IFBM, VLB). Stabilization methods and conditions were varied to study the impact of shortened cold stabilization and elevated cold stabilization temperature.
Results: IFBM results demonstrate that with PSEP cold-stabilization time could be shortened from 9 to 3 days without compromising beer shelf life; after 8 months of storage, beers were still visually clear at 0ºC. When omitting cold stabilization completely a clear beer was produced with approximately 5 months shelf life.
In addition, PSEP treated beers cold stabilized at either 0°C or at 7°C feature same colloidal stability leading to significant energy savings hence reducing CO2 footprint of beer manufacturing. Moreover no differences were found in other quality attributes such as foam and taste, between PSEP stabilized beers and control.
The trials at VLB further demonstrated the excellent flavor stability (based on VLB ‘s 10 indicator chemicals) of PSEP treated beers with short stabilization process at elevated temperature. Since natural antioxidants remained in beer after PSEP stabilization, both endogenous antioxidant potential (EAP) and beverage antioxidant index (BAX) were high.
Discussion: The possible reduction of cold conditioning time with PSEP enables brewers to significantly increase maturation capacity. In addition, energy savings are attainable by increasing the cold-conditioning temperature. PSEP is an environmentally friendly solution for beer stabilization, not only reducing waste stream, but also reducing carbon footprint.

What is new - Semi-industrial scale data from two international institutes demonstrated that by application of a PSEP the brewery capacity can be increased by reducing the cold stabilization process time, without compromising shelf-life or flavor stability. In addition, energy savings are attainable by increasing the cold stabilization temperature, thus reducing the brewery carbon footprint.

 

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Description of topic: Conveyors in bottling plants are not only used for the transportation of bottles. To compensate downtimes of single machines they are required as buffers that need to be controlled with reference to their filling level. Nowadays the filling level can only be detected stepwise with inductive or capacitive switches. To calculate the exact filling level, bottles that enter or exit the buffer need to be counted. To this day sensors for this counting task are missing for multi-lane in- or outlets of machines (e. g. bottle washers, packers).
Materials and methods for data collection: For the presented control approach a sensor system was developed that allows the needed counting of bottles in a bulk. It consists of a CMOS-camera and a LED-bar. Camera pictures of the bottles are analyzed by a FPGA-based (Field Programmable Gate Array) processor. Afterwards the counter value is sent to the PLC (Programmable Logic Control) as an input value for the conveyor control. By an advanced control algorithm, stepless conveyor control of buffers was enabled and implemented to the buffer of a pilot plant. Now the conveyor speed is continuously adapted to the correct filling level.
Results: The exact control of the conveyor speed increased the downtime the buffer can compensate. This improves the buffers efficiency and may increase the efficiency of complete plants up to 5 per cent, as simulation studies verified. Additionally the collision speed of the bottles could be reduced. This resulted in reduced bottle scuffing and considerable lower sound emissions. Overall the continuous conveyor control enables a more evenly operation and reduces the mechanical wear of a bottling plant.
Discussion: The mentioned sensor and the control concept are a completely new approach in controlling bottle conveyors. It will help to defend operators from hearing disorders. Bottling efficiency will be increased and maintenance costs will be reduced in one of the most cost-intensive parts of the brewery, the packaging area.

What is new - During the presented project a new sensor system and a new control concept for bottle conveyors has been developed and implemented. For the first time it is possible to control multi-lane conveyors stepless. This could be the next step of development in controlling bottle conveyors.

 

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Description of topic: Bottling plants are complex lines consisting of several linked machines. To increase their today’s efficiencies between 50 and 75 percent downtime originating components need to be identified. For this purpose brewers desire automatic systems. Due to interdependencies along the different material flows within the line for this is a difficult task . The presented interdisciplinary research project aspired to a solution, which saves resources by avoiding the establishment of a tailored system for each plant and is cheaply adaptable to changes.
Materials and methods for data collection: To obtain a flexible solution, the project followed a model based approach. Instead of installing additional and itself unreliable sensors for condition monitoring, the model based diagnosis system compares the plants behaviour with the behaviour a theoretical model. This model was developed modularly and describes the temporal displacements between the plants components. Inconsistencies between plant and model behaviour allow to detect failures and to locate their reasons. For the plant observation production data was used that could be gained out of common automatic data acquisitions systems in accordance to the “Weihenstephan Standards”.
Results: The validation through simulation and its use in analyzing real data from two different plants has provided evidence that the models really capture the essential features of plant behaviour. Diagnosis algorithms based on the model components were implemented in a software tool. It allows the automatic localization of plant components, which caused downtimes of the filling machine. Technical downtime reasons could be identified with an accuracy of 89 per cent (status quo of September 2008).
Discussion: The results provide an evaluated procedure for automatic down time analysis just by using the generic model components together with a description of the plants structure and its parameters. Furthermore, the project contributed to improving the general conditions of automatic data acquisition.

What is new - While model based diagnosis systems already run successfully in cars or electric power plants, the first realization in food packaging plants and more specifically, bottling plants, is presented. The developed context free model components present the behaviour of a complex bottling of various structures. This cutting-edge modular approach significantly improves the conditions for effective and easily adaptable diagnostic solutions.

 

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Description of topic: Disinfection processes are basic in drink and food producing industries to guarantee a hygienic and safe production. In times of an increasing cost pressure in breweries and increasing energy costs, the use of efficient and economic disinfectants gets more and more to the fore.
Beside common on-site produced disinfectants like ozone, chlorine dioxide and partly ionized air especially electro chemical activated (ECA) disinfectants based on the membrane cell electrolysis are coming up in a broad range of applications from the classical water disinfection up to CIP processes of tanks, lines and machines as well as rinsing and showering steps of bottles, packaging materials and full packs, replacing cost intensive thermal disinfection steps or converted disinfectants.
Materials and methods for data collection: The contribution includes analytical results of different produced stock solutions of several upper named on-site produced disinfectants within their by-products and there microbiological efficiency, as well as their compatibility of materials. Beside this, data of the formation from disinfection by-products especially in case of water disinfection and in the waste water are worked out in due to different disinfection strategies. Further analytical aspects and problems are argued as well as proper monitoring possibilities and difficulties while using on-site produced disinfectants. Finally a risk analysis of the different disinfectants in due to the final beer is given, in case of remaining concentrations in plant equipment, packaging material or the product water. For this several test-brews, data from practical uptakes and laboratory tests are presented.
Results: The formation of by-products is strongly dependant to the water quality. The use in different parts of the breweries demands different approaches.
Discussion: Adhering to regulatory framework water quality and concentration should be taken into consideration. The use of the described disinfectants can lead to a decrease of energy costs in a brewery.

What is new - On site produced disinfectants are used in a higher amount in practice. The presentation shows results of new applications of common disinfectants like chlorine dioxide in rinsing steps as well as a new method in producing disinfectants (membrane cell electrolysis) and their results in practice as well as their possibilities and risks in breweries.

 

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Description of topic: The lautering process in the lauter tun is still a very time consuming process. But for that all, the procedural knowledge about the exact behaviour of the filter cake is still quite unexplored.
Current investigations on the institute show, that a deeper understanding of the behaviour of the particles, of the filter cake and the behaviour of them on each other bring faster and better lautering results.
Materials and methods for data collection: For the investigations, at first an analysis method for the fine mash particles with laser diffraction was developed. On this basis, several tests about the behaviour of the particles during the mashing process were explored. The mashing tests were done with a rheometer and a capillary viscosimeter in laboratory scale. Further investigation factors were extract and beta-glucane-content.
The influences on the resulting mash with a look on viscosity, particle size distribution and extract were investigated in the pilot plant lauter tun of the institute. Beside technological factors like residual extract, turbidity in the wort and lautering time, procedural aspects like the behaviour of the cake height, the distribution of fine and coarse particles, porosity and the flow behaviour were investigated.
Results: The results show the behaviour of the technological factors in dependence on the development of the particle size distribution during the mashing process. The tests in the lauter tun prove a better procedural characterisation of the filtration process and subsequently a basis for better process control of this step.
Discussion: The investigated results give new possibilities for the analysis of the mashing and lautering processes.
Furthermore, with the procedurals looks on the processes help to understand the separation process much better. The results show, that there are e.g. realisable ways for higher flow rates during lautering.

What is new - With the alternative ways of processing and analysis, new possibilities in the brewhouse performance are shown. The applied methods are well known in other industries, but not at all in the brewing sector.

 

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Description of topic: From the experiences of numerous finished fermentation and storage cellars, Krones has developed a new cellar concept. In this abstract, the latest findings and the development of this concept are presented.
Materials and methods for data collection: Among considerations of optimal product quality regarding engineering, technology and efficiency the existing knowledge of a long practical experience was developed. The result of this work meets the various requirements of modern breweries.
Results: The new cellar concept is based on an execution in separate filling and discharging blocks with double seat (ds-) valves. Several tanks can be put on one common pipeline. The number of aggregated tanks can be defined individually. The gas side is designed fully automatic with ds-valves or, alternatively, semiautomatic with tilting bends.
The cellar can be extended independent on tank number and pipe length and therefore is more flexible. The clearly arranged and easily accessible construction facilitates the handling and maintenance. Due to the use of ds-valves directly at the tank outlet, the product content in the not-cooled pipes is reduced to a minimum.
With regard to product safety, the product and CIP-lines are separated leak safely. Product related discharging pipes are equipped with a D/A-water supply in order to minimize the oxygen uptake.
Discussion: Unlike other proposals, Krones represents a philosophy that holistically fulfils the various conditions in today’s brewing industry.
Through specific interconnection of the shortest pipeline routes, those can be cleaned before and after the production. Thereby, product and detergent losses can be reduced to a minimum. A loop displacement of the feed and return line minimizes media mixing. The effectiveness of the CIP plant, therefore, is optimally occupied. A proper cleaning of all pipes as well as the tank outlet (through back flush with high performance) is guaranteed.
Due to the short pipeline routes lower pressure losses at the pump pressure and suction side are generated.

What is new -

 

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Description of topic: The fast progress in information technologies provides large computing power at low cost ratios. That makes it possible to extend and combine - despite the linked increase in required processing power - current modelling approaches in production planning as well as process simulation and optimization. These extended approaches allow for a new evaluation of optimisation problems in the fields of energy management and capacity planning.
Materials and methods for data collection: A new hybrid modelling approach is proposed combining discrete-time and continuous-time modelling. The hybridisation is handled modular allowing the integration of a lot of different modelling types like fuzzy logic and artificial neural networks as well as heuristic search algorithms. The applied programming for an example simulation environment implementing the new approach is scalable from desktop environment to distributed computing applications.
Results: The example simulation environment was applied to a hypothetic brewery in a production planning preliminary test case. Currently it is in use for the optimisation of steam supply in a medium sized brewery. The simulation environment showed full reproductivity and adaption of the targeted problem. A statistical sensitivity analysis suggest (98% confidentiality) full parametric interaction between the modelling modules. Heuristic - tabu and genetic - search algorithms show good convergence and reproductivity. Both tested algorithms find solutions of the best 5 % of the complete solution field with a approximate searchtime reduction of 1/40.
Discussion: One of the main problems of new modelling approaches can be applying them to a real life situation. The currently running optimisation of steam supply shows good results, not only detecting spiking demands but also in combining energy optimisation with capacity planning and scheduling and thus linearising steam and power demand. In the lookout a hybridization in modelling approaches may also bring together different field of process management and economisation.

What is new - The proposed extension and combination of existing approaches for production planning, process simulation and optimization creates a hybrid approach combining discrete-time and continuous-time modelling. Included are also knowledge intensive approaches like artificial neural networks and fuzzy logic. Additionally included heuristic search algorithms reduce computing time. The approach is applicable for modelling energy management and capacity planning problems and combinations thereof.

 

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Description of topic: The market of functional food and beverages is fast developing due to the changing lifestyle of the consumer and a growing dietary awareness. Malted cereals and pseudo cereals are becoming more and more interesting as ingredients for these kinds of functional foods. The aim of this study was to determinate the general levels of relevant substances like phenols, antioxidants, beta-glucans etc in various grains and to determine how their levels change during malting. To be able to optimize the content of these substances during malting a statistical design of experiments approach was used.
Materials and methods for data collection: A micro-malting machine was used to malt barley, rye and buckwheat. Response surface methodology was used to evaluate the impact of the malting parameters temperature and time on the malt quality. Phenolic compounds, Antioxidant activity and Beta Glucan were determined by photometric methods. Arabinoxylan was measured using HPLC.
Results: Compounds with potentially health promoting substances are present in all four investigated grains. However, the impact of malting on the grains differs. Beta-glucan was quickly degraded during malting in barley. In contrast, arabinoxylans in rye were accumulated and became increasingly extractable with longer germination times. The average molecular weight decreased due to enzymatic breakdown. Malting of buckwheat did increase the content of phenolics. For the other two grains, the extracts of the malts contained more phenolics then the unmalted grain. Similar results were found for the antioxidant activity.
Discussion: It is crucial to choose the appropriate raw material and malting conditions for a desired product. Malt high in soluble dietary fibre can be produced from rye, while in barely the relevant beta-glucan is widely degraded even after short germination times. Unmalted buckwheat is a rich source of phenolic compounds, however, malting did not increase it; rye and barley on the other hand can be enriched with phenolic compounds by means of malting.

What is new -

 

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Description of topic: Evaporation of unwanted flavours out of wort is only performed in the hot section (brewhouse) of a brewery until today. It is known from many fields of process engineering that an evaporation at lower temperatures can have many advantages. On the one side the thermal stress can drastically be reduced. On the other side it is in some cases possible that the separation factor of components between steam and liquid increases at lower temperatures. Because of these facts it was researched if an evaporation in the cold section of the brewery brings advantages in the field of wort/beer production.
Materials and methods for data collection: It is known from reaction kinetics that the thermal stress of wort is reduced with decreasing temperature and/or boiling time. This advantage is already obvious. Thus, the vapour-liquid-separation-factors and Henry’s law constants of important off-flavour components in wort were researched at different temperatures below 90 °C with a recirculating equilibrium still.
Results: The results show that the separation factor of many unwanted flavour components drastically increases with decreasing temperature. For example, the separation factor of dimethylsulfide is about 75 at atmospheric boiling conditions, while at 30-35 °C its value is more than 3000. Thus, it is obvious that clearly less wort has to be evaporated in the cold section of a brewery to reach a desired flavour profile in wort. As also the Henry’s law constant is higher at lower temperatures, no high vacuum is needed for an evaporation at low temperatures. This can also be performed by a desorption. The results were proven with an evaporation at a pilot plant in a brewery.
Discussion: The results show that with this new knowledge it is possible to abstain completely from an evaporation of wort before cooling. After the cooling, clearly less then 1% of wort has to be evaporated to reach a perfect flavour profile. This leads to enormous energy savings. In addition the thermal stress of the wort can be reduced to a minimum needed for kinetics.

What is new - For the first time, an evaporation of wort is not performed in the hot section of a brewhouse. A more than effective evaporation can be achieved if it takes place after the cooling of wort at clearly lower temperatures. No thermal energy is needed for an evaporation in the hot section of a brewery anymore and after the cooling of wort, its thermal energy is already fully recovered. Thus, this new process minimizes the needed energy for the evaporation of wort to an absolute minimum.

 

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Description of topic: Beer has never been just about barley. Over the history of brewing, many different starch sources have been used to add flavour and character to beer. With the rapid rise in malt prices, the possibility of barley shortages and consumer demands for natural products, we believe that the time is right to explore brewing with some novel adjuncts. With the philosophy that ‘anything goes’ we selected raw materials to provide natural colour, flavour and potential economical benefits for brewing. This presentation will discuss the successes and failures of these brews, and the lessons learned, while exploring these Alternative raw materials.
Materials and methods for data collection: We will present data from both laboratory scale work (mashes), and also performance in the brewery, as well as a sensory evaluation of the products.
Results: Initially, a wide range of raw materials were compared for extract, filtration performance and for flavour on the laboratory scale. Based on these data, we selected 5 raw materials for brewing trials. To produce a red hue, beetroot was added at 5% to the grist. For extract, carrot, butternut squash, chickpeas and cassava were included as 20% adjuncts. These brews gave us surprises in terms of their brewing performance and flavour, and this talk will describe some of the challenges faced using these raw materials.
Discussion: The key questions asked in this project were: How does the beer appear and taste? How practical is it to brew with this raw material? What are the economic implications? We have shown that combining laboratory scale work, pilot brewing and sensory evaluation is an efficient method to speed up new product development. Having created some interesting tastes, flavours and colours in this work, and we believe that there are undoubtedly many more raw materials that could have a home in the brewery. Our recommendation is to send the new product development team down to the market with an open mind and ask them to give some new materials a try!

What is new - This project is all new work, and has not been presented elsewhere

 

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Description of topic: Due to cost pressure for purchase of High Liquid Maltose (HLM) a customer wants to modify his existing brewhouse for the production of maltose syrup made from barley. The paper will highlight the planning and the process development based on the use of the existing lauter tun for syrup filtration.
Materials and methods for data collection: All engineering work has to consider a double purpose use of the brewhouse. It must be possible to produce either the standard beer brands or maltose syrup from barley. A switch from beer production to maltose syrup has to be made automatically. In a first step the required mashing procedure and an appropriate enzyme mixture has to be developed. After evaluating the economic concentration of the wort after the filtration process in a lauter tun we started the design of the evaporation unit.
Results: The existing lauter tun defines the milling technique. Under these conditions pilot plant trails were made to work out an infusion mashing regime of less than 4 hours allowing 12 brews/day and reaching the project goals regarding sugar composition and turbidity. We achieved a stable industrial process using a mixture of 85 % barley, 15 % malt and a tailor made enzyme complex.
The lauter tun delivers wort with final gravity of 13 °P. Based on these findings the falling film evaporation plant was designed for a final concentration of the syrup at 77 °Brix. To standardize the group-wide use of this maltose syrup the variation of the inlet gravity from the brewhouse must be compensated by using a ‘finisher’ unit after the 4-stage-falling film evaporation.
Discussion: With reference to the customers´ demands the brewhouse was modified to deliver a continuous wort stream to the evaporation plant as well as standard beer brands in normal production. The engineering solution and in detail the connection of the evaporation plant to the brewhouse will be discussed. We will have a special focus on all implemented tools for reduction of energy demand and water consumption of the evaporation plant.

What is new - Realizing the double-purpose function of a brewhouse either producing the standard beer brands or maltose syrup from barley. Infusion mashing procedure for 85 % barley content. Increasing brewhouse utilisation by own production of high maltose syrup.

 

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Description of topic: Yeast fermentation performance is influenced by amino acids. The amount of amino acid of all malt wort is determined by the malting procedure and adjustments at lower mashing temperatures. A tool to influence the amino acid composition is not established. As unmalted barley is used world wide as brewing raw material the aim of this paper was to show which amino acid contribution barley can add to the wort profile. In a system of barley and exogenous enzymes one can imagine that not only the amount but as well the composition can be influenced by the choice of specific enzymes and therefore provides a tool to design a favourable amino acid composition.
Materials and methods for data collection: All standard analysis has been executed according to the Analytica EBC. The amino acid profile was measured by HPLC. ESR analysis has been done at VLB. Lab fermentations have been executed at Novozymes, pilot trials at TUM and Ziemann in Germany.
Results: The results show that wort derived from 100 % barley has a lower amount of amino acids but also a different amino acid profile. By applying the right exogenous proteases the amount can be enhanced to 80 % of all malt wort. According to the absorption ranking from Jones the barley wort profile has 30 % more amino acids in group 1 and 2 but only a small content of prolin. It was shown that for the same fermentation performance a lower amount of amino acid was necessary and it was found that the amount of residual amino acids can be reduced within barley wort fermentation significantly. The paper will show the influence of the different profiles on cell growth and ethanol yield. Pilot trials in 10 hl scale with taste panel results will show the effect on flavour stability and the antioxidative potential.
Discussion: It is possible to influence the amino acid composition of barley wort and therefore all related reactions within the brewing process. Using barley in combination with exogenous proteases can contribute to enhanced fermentation performance and influence the flavour stability.
 
What is new - With a new developed enzyme system it was possible to process a 100 % barley brew. It is now possible to describe the contribution of barley to the amino acid profile of the wort as well as the influence of the fermentation performance and flavour stability of the final beers. It has been shown that barley in combination with exogenous proteases can deliver a favourable amino acid profile which can contribute benefits to the fermentation performance and the beer quality.

 

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Description of topic: The industrial conditions, mainly high hydrostatic pressure, shear forces, etc. may have a great influence on the dynamics of uptake and release of metal ions by yeast. We analysed the ionic content of yeast used many times and also of the relevant worts, during serial repitching into next fermentation cycles performed at industrial scale, comparing the results with those obtained in laboratory scale experiments.
Materials and methods for data collection: The influence of multiple use of yeast slurry (up to 5 times) on the metal ions management was investigated. The fermentation rate and the yield of main fermentation products (ethanol, biomass), together with the concentration of Mg, Zn and Ca ions was analysed. The ionic content of yeast and wort was checked on daily basis. The same working conditions (wort type, fermentation temperature, yeast strain) were applied during industrial fermentation in a 3000 hl fermenters, and the ionic content of wort and yeast was monitored daily throughout the main fermentation. Metal ions concentration was analysed with the use of VARIAN 240FS atomic absorption spectrometer, following wet-pressure digestion in a MARS Xpress microwave system.
Results: Intracellular level of zinc was relatively high at the beginning of the logarithmic phase, reaching the same level of ca. 0,5 mg/g d.m. regardless of the initial value present in yeast at the beginning of each fermentation. Whereas calcium, being required in flocculation, was absorbed by yeast towards the end of fermentation - but only in the case of industrial fermentations.
Discussion: The intensity of metal ions uptake and release is dependent on the fermentation phase changing in subsequent fermentations performed by the same biomass. The ions under consideration were taken up by yeast at the beginning of the process and then slowly released. The biomass took up zinc ions at different rate, reaching the same level (0,5 mg/g d.m.), however the 4th and 5th use of biomass revealed a lower ability to take up zinc ions.

What is new - We showed how uptake and release of metal ions change in the course of industrial serial fermentations. Many authors covered this topic but there are very few publications dealing with the problem at industrial scale. We showed that calcium uptake differs in industrial scale from that at lab scale and proposed an explanation for this. Also zinc uptake pattern at industrial scale seems interesting and proves the fact that serial repitching influences the ability of biomass to take up zinc ions.

 

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Description of topic: In this study, we investigated the effect of the amount and timing of aeration on ester formation. From test brews under various wort aeration conditions, we found that oxygen has both a positive and negative effect on ester formation, which depended on the timing of wort aeration. We assumed that those conflicting effects reflected the two roles of oxygen for yeast growth. This result could be a clue to control the ester formation with the wort aeration process at a commercial scale.
Materials and methods for data collection: We investigated the effect of two aeration procedures. One was aeration with a flotation process, and the other was “delayed” aeration, in which air was injected directly into the fermentation tank after filling. We measured the dissolved oxygen in wort during and after aeration process, and calculated the total dissolved oxygen concentration by yeast (TDOC). Acetate esters and alcohols of products were determined by gas chromatography.
Results: The TDOC in the brew with a flotation process was higher than the brew without a flotation process, in spite of the flow rate of injected air being the same. The amount of esters had a negative correlation with TDOC, and consequently a smaller amount of acetate esters was produced with a flotation process. Whereas when air was added after the filling of the fermentation tank, ester production significantly increased.
Discussion: This result suggested the two roles of oxygen dependent on the timing of consumption by yeast during cell growth. The oxygen consumed in the earliest stage of fermentation would mainly be used to synthesize unsaturated fatty acids, resulting in the reduction of acetate esters. On the other hand, oxygen used for the aerobic respiration during cell cycle would accelerate the synthesis of acetyl CoA and alcohols, and accelerate the formation of ester as a result. We attempted to control the amount of product esters using aeration process and obtained the result which supported our hypothesis, thus indicating that our hypothesis should be true.

What is new -

 

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Description of topic: Gene array analyses show aerobically grown yeast switch off amino acid (aa) biosynthesis and rely solely on amino acid uptake. Anaerobically it’s opposite; amino acid uptake is switched off and yeast depend on biosynthesis. One-C metabolism (serine, glycine) becomes critical for yeast growth and vitality. It also affects production of flavour actives. But simple wort manipulation can overcome aa exclusion anaerobically which in turn profoundly affects ester production.
Materials and methods for data collection: Gene array analyses were carried out on lager, wine and laboratory yeast strains and knock-out yeast mutants. Complementary growth studies, oxidative challenge tests, chemical analyses, and cell wall analyses were performed.
Results: Gcn4p is a transcriptional activator of more than 30 amino acid (aa) biosynthetic genes. We have investigated the role of amino acids and Gcn4p in the shift of yeast from aerobic to anaerobic conditions and found that the gcn4 mutant has an extended lag under anaerobic conditions. This delay is rescued by adding serine or glycine to the medium. Most added serine accumulates in the cell wall mannoprotein. Serine and glycine both act as donors for the one-carbon unit in one-carbon metabolism, which is required for biosynthesis of purines, some amino acids, dTMP and some cofactors. Cell wall structure is a critical adaptation for anaerobiosis. The mannoprotein Cwp2p is essential for aerobic cell wall synthesis. It is replaced by a family of mannoproteins including Tir3 anaerobically. Cwp2p has 10% serine, whereas Tir3p has 23%. This may explain the serine requirement. This is relevant to stuck fermentations and a check-point for commitment to flocculation.
Discussion: Yeast do not synthesise aa under aerobic conditions. But anaerobically the opposite happens - aa biosynthesis and no uptake. Amino acids control ester formation. If aa uptake reverts to the aerobic model, flavour changes will occur. The switch we now report is affected by wort composition. Flavour implications are discussed.

What is new - We report for the first time that aerobic yeast obtain aas solely by uptake, whereas anO2 cells rely solely on biosynthesis. Yet we report it is possible, and feasible, to switch-on amino acid uptake in anO2 cells and that this affects ester formation and ester profile. We think this work has implications for yeast flocculation, vitality and wort preference. This will be useful to maltsters, brewers and wine makers.

 

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Description of topic: During fermentations with lager yeast in High Gravity Glucose Rich (HGGR) worts, high levels of sulphite production can occur. Cloudy worts, or worts rich in trub solids, have been known to diminish the levels of sulphite produced with these fermentations, even under hypoxic conditions, yet it is still a contentious topic in brewing as to exactly what role solids play in regulating sulphite production.
Materials and methods for data collection: Laboratory fermentations with HGGR worts were conducted with the supplementation of untreated trub solids, rich in lipids, and the same trub solids that underwent lipid removal using Soxhlet extraction with petroleum ether. These results were compared to control fermentations and also fermentations where activated carbon was added to provide lipid-free nucleation sites for CO2. To further explore which lipids may be playing a role, a 28-4 resolution IV fractional factorial design was executed studying various common Fatty Acids (FAs) found in wort (16-18 carbon FAs), two phytosterols, and phosphatidycholine (lecithin).
Results: It was clear from the data that the lipid rich solids influenced sulphite production (p-val < 0.05). It was found that three lipids played a role in reducing sulphite (p-val < 0.10) in this experiment: linoleic acid, lecithin, and campesterol.
Discussion: In profiling trub solids for phytosterols, campesterol was found in significant quantities and this could suggest that campesterol is somehow incorporated into cellular membranes of the yeast. This seems highly plausible based on the structure of this phytosterol compared to the main yeast sterol, ergosterol. Finally utilization of methionine and sulphite in these experiments demonstrate interesting patterns and could suggest a possible reason why these lipids play a role in regulating sulphite production.

What is new - The impact of phytosterols on sulphite production during fermentations in high gravity glucose rich worts

 

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Description of topic: Premature yeast flocculation (PYF) is an intermittent brewing fermentation problem that results in incomplete wort fermentation, and is a significant problem for some breweries. When PYF occurs it can cause significant losses in out of specification beer (incompletely fermented beer) to the brewer. The occurrence of PYF appears to be related to certain malt batches, however detection of these problem batches by way of a fermentation test that is problematic and time consuming.
Materials and methods for data collection: Previous research investigations have been directed at identifying the causal wort PYF active components of PYF. These approaches have not been particularly successful over the past 40+ years. Consequently we have approached the problem from a different perspective. That was to use molecular finger printing of malt microbes as a step to identify the microbial taxa that cause PYF by comparing PYF +ve/-ve malts using terminal restriction fragment length polymorphism (T-RFLP). T-RFLP is a rapid, sensitive, sequence-based technique for microbial diversity assessment based on the highly conserved rRNA allowing comparison of the composition of microbial populations.
Results: We have made a significant breakthrough with the T-RFLP approach and concept. Very striking differences in the microbial DNA finger print patterns, particularly for the fungal PCR primers, between PYF +ve/-ve malts are obvious by using the T-RFLP technique. We are currently screening further confirmed PYF +ve/ -ve batches of malt to validate our discovery.
Discussion: The next step is to translate the differences in composition of the fungal taxa between PYF +ve/-ve malts into the identification of the causal PYF organisms. These rRNA sequences would be then used to design PCR primers that would be expected to identify probable PYF malt batches. This approach will also involve validation to ensure that all the PYF associated fungal taxa are identified.

What is new - Significant progress in new method for detecting malt samples that are PYF +ve without the need for a time consuming fermentation test. This test is based on using PCR primers that identify various members of the malt microbiota. Various microbe taxa, particularly some fungal members, are strongly associated with the PYF +ve malt determinations made with conventional fermentation tests.

 

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Description of topic: Lactobacillus brevis comprises strains with diverse metabolic capabilities. Some specialized strains can grow even in highly hopped pils beers without the need of long term adaptation. Other strains develop tolerance upon prolonged hop exposition or remain sensitive. This work sheds light on the molecular mechanisms behind these differences and provides clues for differentiation of "harmless" versus "critical" strains for the brewer.
Materials and methods for data collection: We used genetic analyses, proteomics and physiological tests in beer as well as studies in membrane physiology and cell wall composition to differentiate beer spoiling L. brevis along their beer spoiling potential and to elucidate decisive marker traits for categorizing beer spoiling L. brevis along their relevance for the brewer.
Results: Beyond previously described transmembrane transport-based hop resistance mechanisms, hop adaptation in L. brevis TMW 1.465 is a multifactorial process, which results in changes in metabolism, protein profile, membrane and cell wall composition and intracellular manganese levels. It involves mechanisms to cope with intracellular acidification and divalent cation limitation, redox imbalance and oxidative damage and mechanisms for energy generation and economy, genetic information fidelity and enzyme functionality, and as a result enables beer spoilage.
Discussion: These results were and can further be used to develop rapid testing methods for beer spoiling L. brevis. So far differentiation along the beer spoiling capacity is possible by comparative proteomics, as well as physiological tests employing cellular manganese content or reduction of a formazan upon growth in lager beer. Genetic determinants potentially useful for PCR detection systems were widely spread in all strains with no reference to high hop tolerance. Some of these tests are useful for simple practical applications. The further understanding of hop tolerance requires comparative genomic studies to reveal critical strain differences and new PCR markers.

What is new - Hop tolerance is not only a matter of transport of hop acids or manganese. Rather, divalent cation limitation, redox imbalance and oxidative damage and mechanisms for energy generation and economy, genetic information fidelity and enzyme functionality are decisive for the ability to grow in beer. New simple physiology based tests were developed for categorization of beer spoiling L. brevis.

 

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Description of topic: This paper is to our knowledge the first to use the newly developed Phenotype Microarray (PM) technology to characterize brewery yeasts and to identify nutrient deficiencies. The Phenotype MicroArray platform (PM) that was developed by BIOLOG Inc. was used to study yeast metabolism and sensitivity to stresses. The ability of commercial strains to grow under controlled gas conditions and under hundreds of different metabolic conditions was measured by colorimetric dye chemistry. The rate of growth was measured kinetically in the OmniLog kinetic reader and the resulting data gave detailed information on the metabolic characteristics of the cells as well as their sensitivity to stresses such as salts and pH and chemical inhibitors.
Materials and methods for data collection: Brewing yeast strains were obtained from the UK NCYC yeast collection or were kindly donated by international brewers. Up 10 microtitre plates each having 96 wells containing a defined substrate or inhibitor were inoculated with the chosen yeast strain and incubated aerobically, or under modified gas conditions at 25 degrees Celsius for 72h. The data generated was captured every 15 min and used to generate a kinetic plot for each substrate or inhibitor. Statistical software was then used to compare growth between yeast isolates.
Results: BRI have worked with Biolog to investigate the potential to characterise brewing yeast isolates and to identify phenotypic changes or utilisation of key nutrients that occur during serial re-pitching and storage. We have demonstrated that there are clear changes in yeast phenotype during serial re-pitching. We can characterise individual brewery strains and can identify deficiencies in biochemical pathways for nutrient uptake and utilisation.
Discussion: The development of this technology has allowed us to explore extensively the effect of storage and re-pitching on yeast phenotype and to relate it to performance in the brewery.

What is new - We have clearly demonstrated the potential of PM to characterise individual brewery strains and to identify them. This is difficult to achieve with other genetic techniques like chromosomal fingerprinting and PCR. We have also monitored phenotypic changes and attempted to relate them to brewing yeast performance.

 

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Description of topic: The Hop Research Center Huell which has been founded by the Society of Hop Research in 1926 is one of the leading institutions in agronomic and scientific studies on hops worldwide. Today all research activities are conducted in collaboration with the Bavarian State represented by the Bavarian State Research Center for Agriculture. Key aspects of this work are the breeding and development of new hop varieties, plant protection, chemical analyses to ensure brewing quality and trials concerning technical issues of hop production. Main emphasis is put on the development of new hop varieties which meet the demands of hop growers and brewers as well.
Materials and methods for data collection: The various breeding programs draw upon the broad variability of the genetic resources available including wild hop germ plasm. Based on classical cross breeding the selection of breeding lines and future cultivars is focused on plants with superior and broad resistance to diseases and pests, fine aroma or high alpha quality and high yield. The whole breeding process is assisted and accelerated by innovative selection techniques, in recent years especially by using molecular markers for disease resistance.
Results: Considerable progress in breeding could be achieved in the Huell aroma cultivars Saphir, Opal and Smaragd by maintaining noble aroma characteristics and improving disease resistance and agronomic performance. Herkules, the new Huell high alpha cultivar provides exceptional high alpha acid yield while giving a harmonious, not too strong bitterness to the beer.
Discussion: Saphir, Opal and Smaragd increase the broad range of fine Huell aroma varieties available for brewers worldwide to create beers with their own typical flavor and aroma expressed in the various beer types. Herkules with its high alpha acid contents and its high storage stability provides considerable economic benefits. These Huell varieties fulfil the brewers` demands for top raw material quality and food safety which will increase their competitiveness on the market.

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