Abstract: Normal gravity wort and high gravity wort with different nitrogen levels were used to examine their effects on the fermentation performance of brewer’s yeast and the formation of flavor volatiles. Results showed that both the wort gravity and nitrogen level had significant impacts on the growth rate, viability, flocculation, and gene expression of brewer’s yeast and the levels of flavor volatiles. The sugar (glucose, maltose, and maltotriose) consumption rates and net cell growth decreased when high gravity worts were used, while these increased with increasing nitrogen level. Moreover, high gravity resulted in lower expression levels of ATF1, BAP2, BAT1, HSP12, and TDH, whereas the higher nitrogen level caused higher expression levels for these genes. Furthermore, the lower nitrogen level resulted in increases in the levels of higher alcohols and esters at high wort gravity. All these results demonstrated that yeast physiology and flavor balance during beer brewing were significantly affected by the wort gravity and nitrogen level.

Abstract: Beer is a beverage consumed worldwide. It is produced from cereals (barley or wheat) and contains a wide array of bioactive phytochemicals and nutraceutical compounds. Specifically, high melatonin concentrations have been found in beer. Beers with high alcohol content are those that present the greatest concentrations of melatonin and vice versa. In this study, gel filtration chromatography and ELISA were combined for melatonin determination. We brewed beer to determine, for the first time, the beer production steps in which melatonin appears. We conclude that the barley, which is malted and ground in the early process, and the yeast, during the second fermentation, are the largest contributors to the enrichment of the beer with melatonin.

Abstract: This study examined the performance of rice and buckwheat when malted under various temperature conditions and for different lengths of time. The mashed malts produced from both rice and buckwheat contained a wide spectra of sugars and amino acids that are required for yeast fermentation, regardless of malting temperature. At the germination temperatures of 20, 25, and 30 °C used, production of reducing sugars and free amino nitrogen (FAN) followed similar patterns. This implies that temperature variations, experienced in different countries, will not have an adverse effect on the production and release of amino acids and sugars, required by yeast during fermentation, from these grains. Such consistency in the availability of yeast substrates is likely to reduce differences in processing when these malts are used for brewing. This study revealed that, while rice malt consistently produced more maltose than glucose, buckwheat malt gave several times more glucose than maltose, across all germination temperatures. Buckwheat malt also produced more soluble and free amino nitrogen than rice malt. Unlike sorghum, which has gained wide application in the brewing industry for the production of gluten-free beer, the use of rice and buckwheat is minimal. This study provides novel information regarding the potential of rice and buckwheat for brewing. Both followed similar patterns to sorghum, suggesting that they could play a similar role to sorghum in the brewing industry. Inclusion of rice and buckwheat as brewing raw materials will increase the availability of suitable materials for use in the production of gluten-free beer, potentially making it more sustainable, cheaper, and more widely available.

Abstract: Beer is a very complex beverage, and the objective evaluation of beer flavour is a skill that many breweries can ill afford to be without. This chapter provides insights into the origins, chemistry and sensory character of the most common beer components. Details of the main ingredients used in brewing are described, with the processes used to produce them. The influence of water composition, the chemistry behind the formation of malt flavour and colour and the key flavours derived from hops and yeast are described. This section also outlines the brewing process and how different brewing practices impact on the flavour and style of the beer. The most common off-flavours encountered in beer are also described, and guidelines on sensory evaluation practices in breweries are offered.

Abstract: Saccharomyces pastorianus FBY0095 was mutated and variants were selected for efficient very high gravity brewing using 15% (w/v) maltose and 15% (w/v) ethanol. Two useful variants were obtained of which one (L6) had growth, wort consumption and ethanol production rates of 0.036, 1.13 and 0.49 g l−1 h−1, respectively. The corresponding results for the wild type were 0.028, 0.98 and 0.4 g l−1 h−1, respectively. The vitality of the variant (expressed as acidification power) was 2.5 while that of the wild type was 2.3. There was also an obvious improvement on flavor of resulting beer when using L6 and the other variant.

Abstract: In a small-scale protocol, the mashing conditions used were found to have important influences on malt quality parameters, including extract, fermentability, and the levels of wort free amino nitrogen (FAN) and â-glucan. Understanding this relationship is important in determining and prioritizing malt components for malt quality assessment. The impact of mash-in temperatures of 62.5–75.0°C was assessed on a modernized small-scale mash program whose key parameters included grist milling at 0.7 mm by disc mill, addition of CaSO 4 (0.3 mM) to water, grist/water ratio of 1:3, 60 min duration of the initial phase of mashing, and the completion of mashing at 74°C. Wort â-glucan and total protein levels were relatively stable, whereas FAN progressively decreased across the temperature range studied. Maximal fermentability was obtained at a mash-in temperature of 65°C. It was observed that malts containing the most thermostable â-amylase type, Sd2H, produced more fermentable worts and that these mashes maintained a greater degree of fermentability at the higher mash-in temperatures. At mash-in temperatures greater than 65°C, extract slowly decreased, whereas the level of wort total fatty acids increased substantially. The levels of linoleic (C18:2) and linolenic (C18:3) acids increased, whereas the level of palmitic (C16:0) and stearic (C18:0) acids declined at mash-in temperatures above 65°C. For yeast fermentation performance, C18:2 is a key nutritive component provided by wort. It was observed that malt samples from different barley varieties produced a range of levels of wort total fatty acid contents, although the greater proportion of this variation could be attributed to between sample variation at mash-in temperatures below 65°C. However, at mash-in temperatures above 65°C, the varietal sample became substantially more important in determining fatty acid content and composition. In both small-scale and commercial worts, wort boiling and trub removal reduced the level of wort fatty acids by up to 85 percentage points and increased the proportion of C16:0 while decreasing the proportion of C18:2. This effect of wort boiling was more variable with commercial brewery worts that were also more variable in the initial levels of total fatty acids and were not as consistent with respect to the extent of trub removal. In particular, the level and composition of wort fatty acids is well known to impact on yeast fermentation performance and generation of flavor-active esters. As such, brewers with a greater understanding of the determinants of the level and composition of the fatty acids in the wort from which they were brewing could potentially produce beer more efficiently and closer to their desired quality specifications.

Abstract: The characteristic buttery taste of diacetyl has long been a major problem in the brewing industry, and the foam stability of unpasteurized beer is often influenced by proteinase A (PrA), which is encoded by PEP4 and released from yeast cells into beer during brewing. A recombinant industrial brewer’s yeast strain that reduces the diacetyl content of beer and improves foam stability was constructed. We constructed a PGK1p-ILV5-PGK1t expression cassette, which was introduced into one of the PEP4 alleles via PCR-mediated homologous recombination. Then, the second PEP4 allele was disrupted using the Cre-loxP recombination system, and the recombinant strain was designated as S-CSIK12. The results show that the diacetyl production of S-CSIK12 is always lower than that of the host strain at all stages of beer fermentation. In addition, brewing with S-CSIK12 reduced the PrA activity of the final beer by 44 % compared with that using the wild-type strain. The head retention of the beer brewed with S-CSIK12 (260 ± 2 s) was better than that of the host strain S-6 (212 ± 3 s). Considering that more PrA is released from yeast cells during the final stage of main fermentation and that the timing of yeast cropping is determined by diacetyl reduction, brewing with strains that have low diacetyl production also reduced the PrA activity of the beer and improved its head retention. The present study provides reference for the brewing industry as well as research on the diacetyl reduction and foam stability of beer.

Abstract: The volumetric productivity of the beer fermentation process can be increased by using a higher pitching rate (i.e., higher inoculum level). Next to this, high-gravity brewing has become a standard...

Abstract: In order to improve the permeability of yeast cell membrane, pulsed electric fields (PEF) was applied in extracting protein from beer waste brewing yeasts (BWBY). Through investigation of three independent variables, including electric field strength (10 to 50 kV/cm), pulse numbers (2 to 16 μs), and liquid-solid ratio (20:1 to 60:1), the optimal extraction parameters for protein were obtained by one-factor-at-a-time (OFAT) experiment and quadratic regression orthogonal design. The results showed that the extraction yield of protein could reach 2.788 ± 0.014% when electric fields intensity was chosen by 10 kV/cm, pulse number was 8, and liquid-solid ratio was of 40:1. Meanwhile, PEF method was a novel and promising method to extract protein from waste beer yeast which will benefit food and agriculture industry. The article mainly focuses on the extraction of dissoluble protein from waste beer yeasts by PEF. PEF could be considered as a highly efficient and energy saving technique to extract bio-component from raw materials. Key words: Pulsed electric field (PEF), beer waste brewing yeast (BWBY), protein, regression model.

Abstract: Our study showed that sorghum and millet followed a similar pattern of changes when they were malted under similar conditions. When the malt from these cereals was mashed, both cereal types produced wide spectra of substrates (sugars and amino acids) that are required for yeast fermentation when malted at either lower or higher temperatures. At the germination temperatures of 20, 25, and 30 °C used in malting both cereal types, production of reducing sugars and that of free amino nitrogen (FAN) were similar. This is an important quality attribute for both cereals because it implies that variation in temperature during the malting of sorghum and millet, especially when malting temperature is difficult to control, and also reflecting temperature variations, experienced in different countries, will not have an adverse effect on the production and release of amino acids and sugars required by yeast during fermentation. Such consistency in the availability of yeast food (substrates) for metabolism during fermentation when sorghum and millet are malted at various temperatures is likely to reduce processing issues when their malts are used for brewing. Although sorghum has gained wide application in the brewing industry, and has been used extensively in brewing gluten-free beer on industrial scale, this is not the case with millet. The work described here provides novel information regarding the potential of millet for brewing. When both cereals were malted, the results obtained for millet in this study followed patterns similar to those of sorghum. This suggests that millet, in terms of sugars and amino acids, can play a role similar to that of sorghum in the brewing industry. This further suggests that millet, like sorghum, would be a good raw material for brewing gluten-free beer. Inclusion of millet as a brewing raw material will increase the availability of suitable materials (raw material sustainability) for use in the production of gluten-free beer, beverages, and other products. The availability of wider range of raw materials will not only help to reduce costs of beer production, but by extension, the benefit of reduced cost of production can be gained by consumers of gluten-free beer as the product would be cheaper and more widely available.

Abstract: Fusarium culmorum infected malt is capable of entering into the brewing supply chain and have a major impact on the processability and quality of beer if present at high initial loads. In this stud...

Abstract: Beer is considered to be a good source of antioxidants. The composition and the quantity of the antioxidant compounds depend not only on the qualities of the raw materials, but also on the technology processes. Barley and malt represent the main source of antioxidant compounds in beer and the contribution of the hop antioxidants is lower. The influence of the mashing process on the antioxidant activity and polyphenol concentration is crucial. The antioxidant state of the sweet wort and the hopped wort are dependent on the technology processes and the raw materials used. The spontaneous sorption of polyphenols onto wort dregs and the polymerization of catechin and epicatechin lead to decreasing concentrations of individual polyphenols in the final beer. Two methods, based on electron spin resonance were used to determine antioxidant activity. These were the DPPH (2,2-diphenyl-1-picryl-hydrazyl) assay and the ‘lag time’ assay using free radical spin-trapping agent PBN (N-tert-butyl-α-phenylnitrone). HPLC with CoulArray detection was used to measure the concentration of the individual polyphenols. This study focused on the antioxidant compounds and on the correlation of their concentrations with the values of total antioxidant activity depending on the mashing process. A good correlation was found between the decline in the concentrations of DPPH (expressed as ARA2) and concentrations of catechin and epicatechin (in sweet wort samples R2 = 0.970, R2 = 0.961, respectively, and in hopped wort samples R2 = 0.949, R2 = 0.956 respectively). Copyright © 2012 The Institute of Brewing & Distilling

Abstract: The brewing industry is facing an ever increasing challenge to become more cost-effective, while at the same time maintaining or improving product quality. Brewing with unmalted oats (Avena sativa ...

Abstract: The invention discloses a mixed grain rice vinegar and a production method of the mixed grain rice vinegar. The mixed grain rice vinegar is a liquid product prepared from black tartary buckwheat, oat, broomcorn, wheat, black glutinous rice and white corn serving as main materials as well as sticky rice and a plurality of Chinese herbal medicines serving as auxiliary materials through fermentation together. The production method comprises the following steps of: cleaning the sticky rice, and then soaking and steaming; respectively crushing the Chinese herbal medicines, the black tartary buckwheat, the oat, the broomcorn, the wheat, the black glutinous rice and the white corn; mixing according to proportion and fermenting for 15 days to obtain a brewing mass; turning over and mixing the brewing mass and performing acidification and fermentation twice; ageing mature brewing mass for three months; then placing the aged brewing mass into a vinegar sprinkling pond; sprinkling cold boiled water slowly, soaking, discharging the vinegar liquid from the bottom of the pond to obtain raw vinegar; and finally, heating the raw vinegar, cooling and bottling, checking out to obtain a finished product. The mixed grain rice vinegar has a health-care function, is natural and pollution-free, can be used for cooking as a seasoning in various occasions such as homes, dining rooms, restaurants and tourist sites. In addition, the mixed grain rice vinegar is delicious in taste, has pure flavor, is soft and lasting in aftertaste, is mellow and sweet, is rich in nutrition and has a unique style.

Abstract: In the present work, a practical method for determination of the basic physicochemical parameters of beer real extract, alcohol and biomass concentration based on the amount of produced CO2 during the fermentation is investigated. The method was applied for determination of biomass concentration in immobilized preparations after its approbation with analytical data for beer fermentations with free cells. The kinetics parameters of the fermentation were determined with 3 of the most used kinetic models. The differences between beer fermentations with free and immobilized cells were investigated. The effect of yeasts immobilization on brewing process was defined.

Abstract: The invention relates to a breeding method of brewed wine, and in particular relates to a breeding method of dry type red rice yellow millet wine. The method comprises the following raw materials in parts by weight: 100 parts of sticky rice, 3 parts of red rice vinasse distillate spirit, 8 parts of red rice power, 3 parts of rhizopus rice flour, 0.05 part of angel wine high active dry yeast BV818and 0.05 part of angel yellow millet wine high active dry yeast. The method comprises the following steps of: steaming rice, pouring rice and building nest, rushing red rice vinasse distillate spirit, cleaning in an extracting way, adjusting components of saccharification solution, adding mixed yeast solution, fermenting by means of feed supplement in batches, and blending in a filtering way, so that the dry type red rice yellow millet wine can be brewed. With the adoption of the method provided by the invention, the brewed dry type red rice yellow millet wine is red and cleaning in appearance, has the composite aroma between the fruit aroma of the honey balm and the special aroma of the red rice yellow millet wine, and is refreshing and pleasant in taste.

Abstract: It has unexpectedly been found that Pichia spp strains have advantageous properties useful in the beer fermentation process In particular, Pichia spp yeast strains can be combined with normal beer yeast strains and different hop varieties in a fermentation process to produce synergistic effects - namely, the increased production of esters in the fermentation product More specifically, the yeast can be used to produce increased levels of isoamyl acetate, isobutyl acetate, ethyl propionate, ethyl valerate, ethyl butyrate, ethyl decanoate and ethyl octanoate in beer In addition, the Pichia spp strain interacts differently with different hop varieties, so the flavor profile of beer can be tuned by using different combinations of Pichia spp strains and hops The present invention relates to a method of brewing beer using a Pichia spp yeast strain and at least one hop variety, a beer obtainable by such a method and use of a Pichia spp yeast strain according to the present invention

Abstract: Aims: In this study, we investigated the relationship between the ability of lager brewing yeast strains to tolerate oxidative stress and their ability to produce oxidative stable model beer. Methods and Results: Screening of 21 lager brewing yeast strains against diamide and paraquat showed that the oxidative stress resistance was strain dependent. Fermentation of model wort in European Brewing Convention tubes using three yeast strains with varying oxidative stress resistances resulted in three model beers with different rates of radical formation as measured by electron spin resonance in forced ageing experiments. Interestingly, the strain with the lowest oxidative stress resistance and lowest secretion of thioredoxin, as measured by Western blotting, resulted in the highest uptake of iron, as measured by inductively coupled plasma-mass spectrometry, and the slowest formation of radicals in the model beers. Conclusions: A more oxidative stable beer is not obtained by a more-oxidative-stress-tolerant lager brewing yeast strain, exhibiting a higher secretion of thioredoxin, but rather by a less-oxidative-stress-tolerant strain, exhibiting a higher iron uptake. Significance and Impact of the Study: To obtain lager beers with enhanced oxidative stability, yeast strains should be screened for their low oxidative stress tolerance and/or high ability to take up iron rather than for their high oxidative stress tolerance and/or high ability to secrete thioredoxin.

Abstract: The vicinal diketones (VDK), such as diacetyl and 2,3-pentandione, impart an unpleasant butter-like flavour to beer. Typically, these are required to be reduced below the flavour thresholds during the maturation (lagering) stages of the brewing process. To shorten beer maturation time, we constructed a self-cloning, bottom-fermenting yeast with low VDK production by integrating ILV5, a gene encoding a protein that metabolizes α-acetolactate and α-aceto-α-hydroxybutyrate (precursors of VDK). A DNA fragment containing Saccharomyces cerevisiae-type ILV5 was inserted upstream of S. cerevisiae-type ILV2 in bottom-fermenting yeast to construct self-cloning strains with an increased copy number of ILV5. Via transformation, ILV2 was replaced with the sulfometuron methyl (SM) resistance gene SMR1B, which differs by a single nucleotide, to create SM-resistant transformants. The wort fermentation test, using the SC-ILV5-homo inserted transformant, confirmed a consecutive reduction in VDK and a shortening period during which VDK was reduced to within the threshold. The concentrations of ethyl acetate, isoamyl acetate, isoamyl alcohol, 1-propanol, isobutyl alcohol and active isoamyl alcohol (flavour components) were not changed when compared with the parent strain. We successfully constructed self-cloning brewer's yeast in which SC-ILV5 was homo-inserted. Using the transformed yeast, the concentration of VDK in fermenting wort was reduced, whereas the concentrations of flavour components were not affected. This genetically stable, low VDK-producing, self-cloning bottom-fermenting yeast would contribute to the shortening of beer maturation time without affecting important flavour components produced by brewer's yeast. Copyright © 2012 John Wiley & Sons, Ltd.

Abstract: Genetic engineering is widely used to meliorate biological characteristics of industrial brewing yeast. But how to solve multiple problems at one time has become the bottle neck in the genetic modifications of industrial yeast strains. In a newly constructed strain TYRL21, dextranase gene was expressed in addition of α-amylase to make up α-amylase’s shortcoming which can only hydrolyze α-1,4-glycosidic bond. Meanwhile, 18s rDNA repeated sequence was used as the homologous sequence for an effective and stable expression of LSD1 gene. As a result, TYRL21 consumed about twice much starch than the host strain. Moreover TYRL21 speeded up the fermentation which achieved the maximum cell number only within 3 days during EBC tube fermentation. Besides, flavor evaluation comparing TYRL21 and wild type brewing strain Y31 also confirmed TYRL21’s better performances regarding its better saccharides utilization (83% less in residual saccharides), less off-flavor compounds (57% less in diacetyl, 39% less in acetaldehyde, 67% less in pentanedione), and improved stability index (increased by 49%) which correlated with sensory evaluation of final beer product.

Abstract: Brewing and bioethanol production with raw grain and exogenous enzymes produces wort with satisfactory hot water extract (HWE). However, the free amino nitrogen (FAN) and mineral content can be too low, owing to low protein digestibility (PD) and phytate–mineral chelation, respectively. This study evaluated the potential for improvement in yeast nutrition in raw whole sorghum and maize brewing and bioethanol production by genetic modification (GM) of sorghum to improve PD and reduce phytate content, and by treatment with exogenous phytase. While phytase addition decreased sorghum spent grain phytate content (88%) and content of minerals (17 to 59%; i.e. increased wort mineral content), it did not affect maize phytate spent grain mineral content or HWE significantly. However, phytase addition did increase maize wort FAN (20%), sorghum HWE (2.8 percentage points) and wort FAN (23%). GM sorghum gave reduced spent grain mineral contents (11–38%), increased HWE (5.5 percentage points) and wort FAN (71%). Hence, genetic modification of sorghum to improve PD and reduce phytate content has considerable potential in raw grain brewing and bioethanol production to improve yeast nutrition. Copyright © 2012 The Institute of Brewing & Distilling

Abstract: The invention discloses a brewing technology of blueberry fruit beer. The brewing technology comprises the step of adding blueberry juice of which the volume is 8%-12% of the total volume of the blueberry fruit beer when residual sugar in delicate beer is reduced to 3.6 degrees Bx in a post-fermentation process, wherein the blueberry juice is prepared by the steps of pulping blueberries into the blueberry pulp, centrifugally filtering the blueberry pulp, taking liquid supernatant, and adding a certain proportion of trehalose into the liquid supernatant. According to the brewing technology, the blueberry juice is added in the post-fermentation process, so that the problems of discordance in fruit juice fragrance and taste, poor non-biological stability, nutrient loss and the like caused by the adding of the blueberry juice after wort is cooled or when the wort is fermented can be solved, and the brewed blueberry fruit beer is bright and shining in color and luster, fine and smooth in foam, full-bodied in fruit fragrance and mellow and normal in mouthfeel, and has not only the fragrant and refreshing beer flavor, but also the unique health function of the blueberries.

Abstract: The invention relates to a wine making production method and belongs to the technical field of production process of medical wine having functions of disease treatment and prevention and healthcare The medical wine production method: mixing natural precious Chinese herbal medicines with raw materials prepared and brewed to ferment according to the proportion of 10:100 or 30:100, brewing at the temperature of 20-30 DEG C and at proper humidity The medical wine production method has the advantages that Chinese herbal medicine and grains for brewing are mixed directly according to correct proportion at proper temperature and humidity to make medical wine, quality of the medical wine is improved, taste is improved, and the effects of disease treatment and prevention and healthcare are realized