Showing papers on "Brewing published in 2008"
TL;DR: The role of brewing yeast in the beer-making process is reviewed and its importance as the main character is highlighted, finding that these functions are focused on supporting the supply of yeast requirements for fermentation and ultimately to maintain the integrity of the product.
Abstract: Historically, mankind and yeast developed a relationship that led to the discovery of fermented beverages. Numerous inventions have led to improved technologies and capabilities to optimize fermentation technology on an industrial scale. The role of brewing yeast in the beer-making process is reviewed and its importance as the main character is highlighted. On considering the various outcomes of functions in a brewery, it has been found that these functions are focused on supporting the supply of yeast requirements for fermentation and ultimately to maintain the integrity of the product. The functions/processes include: nutrient supply to the yeast (raw material supply for brewhouse wort production); utilities (supply of water, heat and cooling); quality assurance practices (hygiene practices, microbiological integrity measures and other specifications); plant automation (vessels, pipes, pumps, valves, sensors, stirrers and centrifuges); filtration and packaging (product preservation until consumption); distribution (consumer supply); and marketing (consumer awareness). Considering this value chain of beer production and the ‘bottle neck’ during production, the spotlight falls on fermentation, the age-old process where yeast transforms wort into beer.
255 citations
TL;DR: In this article, a survey of the occurrence of hydroxycinnamic acids and volatile phenols in a variety of beer styles was presented, and the contribution of 4-vinylguaiacol to the overall flavour perception of top-fermented specialty beers was shown.
191 citations
TL;DR: This paper reviews the scientific knowledge about germination/malting of oat with special emphasis on changes in grain characteristics and examines the main goals of malting and secondary metabolites produced during germination.
Abstract: The biochemical and physiological reactions of germination have long been utilised to produce barley malt for brewing and other purposes. Also some oat malt has been produced as raw-material of ale and stout production. The main goals of malting have been the degradation of grain storage components to soften the kernel structure, synthesis of amylolytic enzymes and production of nutrients for brewing yeast. Also flavour and colour attributes have been important. During the recent years interest has arisen also in the secondary metabolites produced during germination, which can have valuable health promoting properties and act as bioactive or functional compounds in foods. By using a tailored germination/malting process a desired combination of valuable properties may be obtained in germinating grains or seeds. All this requires knowledge and know-how of the germination process and the biochemistry behind it. This paper reviews the scientific knowledge about germination/malting of oat with special emphasis on changes in grain characteristics.
154 citations
TL;DR: It is demonstrated that the initial wort density can determine the final concentration of important volatile aroma compounds, thereby allowing beneficial adaptation of the flavour of beer.
Abstract: During fermentation, the yeast Saccharomyces cerevisiae produces a broad range of aroma-active substances, which are vital for the complex flavour of beer. In order to obtain insight into the influence of high-gravity brewing and fermentation temperature on flavour formation, we analysed flavour production and the expression level of ten genes (ADH1, BAP2, BAT1, BAT2, ILV5, ATF1, ATF2, IAH1, EHT1 and EEB1) during fermentation of a lager and an ale yeast. Higher initial wort gravity increased acetate ester production, while the influence of higher fermentation temperature on aroma compound production was rather limited. In addition, there is a good correlation between flavour production and the expression level of specific genes involved in the biosynthesis of aroma compounds. We conclude that yeasts with desired amounts of esters and higher alcohols, in accordance with specific consumer preferences, may be identified based on the expression level of flavour biosynthesis genes. Moreover, these results demonstrate that the initial wort density can determine the final concentration of important volatile aroma compounds, thereby allowing beneficial adaptation of the flavour of beer.
153 citations
TL;DR: Recent development in reactor design and understanding of immobilized cell physiology, together with application of novel carrier materials, could provide a new stimulus to both research and application of this promising technology.
Abstract: Traditional beer fermentation and maturation processes use open fermentation and lager tanks. Although these vessels had previously been considered indispensable, during the past decades they were in many breweries replaced by large production units (cylindroconical tanks). These have proved to be successful, both providing operating advantages and ensuring the quality of the final beer. Another promising contemporary technology, namely, continuous beer fermentation using immobilized brewing yeast, by contrast, has found only a limited number of industrial applications. Continuous fermentation systems based on immobilized cell technology, albeit initially successful, were condemned to failure for several reasons. These include engineering problems (excess biomass and problems with CO2 removal, optimization of operating conditions, clogging and channeling of the reactor), unbalanced beer flavor (altered cell physiology, cell aging), and unrealized cost advantages (carrier price, complex and unstable operation). However, recent development in reactor design and understanding of immobilized cell physiology, together with application of novel carrier materials, could provide a new stimulus to both research and application of this promising technology.
123 citations
TL;DR: In this article, the effects of mashing variables such as mashing-in temperature, time and pH, mash thickness, grist coarseness and composition, and stirring regime on the release of ferulic acid were examined.
73 citations
TL;DR: The application of antimicrobial-producing LAB at various points in the malting and brewing process could help to negate the problem of spoilage, providing an added hurdle for spoilage organisms to overcome and leading to the production of a higher quality beer.
73 citations
TL;DR: The available data suggest that the yeast cell does not experience oxidative stress during industrial brewery handling, and this information may be taken into consideration when setting parameters for industrial brewery fermentation.
Abstract: Commercial brewing yeast strains are exposed to a number of potential stresses including oxidative stress. The aim of this investigation was to measure the physiological and transcriptional changes of yeast cells during full-scale industrial brewing processes with a view to determining the environmental factors influencing the cell's oxidative stress response. Cellular antioxidant levels and genome-wide transcriptional changes were monitored throughout an industrial propagation and fermentation. The greatest increase in cellular antioxidants and transcription of antioxidant-encoding genes occurred as the rapidly fermentable sugars glucose and fructose were depleted from the growth medium (wort) and the cell population entered the stationary phase. The data suggest that, contrary to expectation, the oxidative stress response is not influenced by changes in the dissolved oxygen concentration of wort but is initiated as part of a general stress response to growth-limiting conditions, even in the absence of oxygen. A mechanism is proposed to explain the changes in antioxidant response observed in yeast during anaerobic fermentation. The available data suggest that the yeast cell does not experience oxidative stress during industrial brewery handling. This information may be taken into consideration when setting parameters for industrial brewery fermentation.
72 citations
TL;DR: In this paper, the importance of manganese ions and their radical formation via the respective Fenton and Haber-Weiss reactions was confirmed, showing that manganous shows a similar radical-promoting effect to that seen with iron and copper.
Abstract:
In this study, the importance of iron and copper ions and their radical formation via the respective Fenton and Haber-Weiss reactions was confirmed. Of the other heavy metals present in the brewing process in relevant concentrations, the impact of manganese ions on beer flavour stability has been elucidated. In contrast to iron and copper, manganese ions are not removed from wort or beer to any great extent during the process. Additionally, manganese shows a similar radical-promoting effect to that seen with iron and copper. Its reactivity, and typically higher concentration than the other two metals in beer, appear to make manganese an especially potent pro-oxidant in beer. The results of the investigation clearly indicate that there are other heavy metals influencing the stale flavour characteristics of beer, in addition to the well-known metals, iron and copper. In contrast to the aforementioned ions, manganese does not enter the product by being leached out of a tank or from piping materials, but rather comes from the cereals employed in brewing. This finding, concerning the importance of manganese as a redox system in beer staling, can serve as a basis for a different approach in the choice of raw materials.
70 citations
TL;DR: In a number of cases the transcriptional response of genes was not consistent with their known responses to glucose, suggesting a degree of complexity during brewery fermentation which cannot be replicated in small‐scale wort fermentations or in laboratory experiments involving defined media.
Abstract: The fermentable carbohydrate composition of wort and the manner in which it is utilized by yeast during brewery fermentation have a direct influence on fermentation efficiency and quality of the final product. In this study the response of a brewing yeast strain to changes in wort fermentable carbohydrate concentration and composition during full-scale (3275 hl) brewery fermentation was investigated by measuring transcriptome changes with the aid of oligonucleotide-based DNA arrays. Up to 74% of the detectable genes showed a significant (p
TL;DR: In this article, the influence of a XN-enriched hop product on the content of XN and isoxanthohumol (IXN) in pale and dark beers was investigated.
Abstract: J. Inst. Brew. 114(3), 246–256, 2008 Based on the health-promoting properties of xanthohumol (XN), the production of an enriched beer in this substance would be of interest to the brewing industry, from the perspective of pointing out the benefits that beer could bring consumer health. For that purpose, in this work efforts were applied to produce a beer enriched in XN. Also investigated was the influence of a XN-enriched hop product on the content of XN and isoxanthohumol (IXN) in pale and dark beers. It was verified that XN was largely converted into IXN during wort boiling. However, the use of dark malts revealed a positive effect on the thermal isomerisa-tion of XN. These results are indicative of the isomerisation-inhibiting effect of the stout production process, which resulted in high levels of XN in the beer. Further losses of XN were due to incomplete extraction from the hops into the wort, adsorption to insoluble malt proteins and adsorption to yeast cells during fermentation. It was possible to produce a dark beer enriched in XN (3.5 mg/L) by using coloured malt (caramel malt, roasted malt and roasted malt extract) and a special XN hop extract combined with late hop usage during wort boiling.
16 May 2008-Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment
TL;DR: Special attention is drawn to the role of metals in beer and brewing, possible metal associations, methods of beer preparation before analysis on the total metal content, and approaches to metal partitioning in beer.
Abstract: Major, minor and trace metals are important in beer fermentation since they supply the appropriate environment for yeast growth and influence yeast metabolism. A real concern is the content of copper (Cu) and iron (Fe), which are involved in beer conditioning and ageing through reactions resulting in formation of reactive oxygen species. The reactive oxygen species readily oxidize organic compounds present in beer, changing the quality of foaming and the flavour stability of beer. In view of brewing technology and beer processing, knowledge regarding functions of metals and their speciation in brewing liquors and beer is of special significance. Metals in beer also have a certain nutritional importance, but their actual effect related to beer consumption depends on the type of species they form with low and high molecular mass organic ligands which naturally occur in beer. This review covers the determination and fractionation of metals in beer using atomic spectrometry methods. Special attention is drawn to the role of metals in beer and brewing, possible metal associations, methods of beer preparation before analysis on the total metal content, and approaches to metal partitioning in beer.
TL;DR: In this article, the behaviors of 3-mercaptohexan-1-ol (3MH) and 3MHA during brewing processes were examined to establish their contributions to the distinctive beer aroma.
Abstract: The behaviors of 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA) during brewing processes were examined to establish their contributions to the distinctive beer aroma. In hops, 3MH wa...
TL;DR: Surprisingly, a high catalase dosage caused a significant, 20% reduction of the initial rate of radical formation, whereas superoxide dismutase had no effect on the oxidation rates, suggesting that hydrogen peroxide and superoxide are not the only intermediates that play a role in the oxidative reactions occurring during aerobic oxidation of sweet wort.
Abstract: An electron spin resonance (ESR)-based method was used for evaluating the levels of radical formation during mashing and in sweet wort. The method included the addition of 5% (v/v) ethanol together with the spin trap alpha-4-pyridyl(1-oxide)- N- tert-butylnitrone (POBN) to wort, followed by monitoring the rate of formation of POBN spin adducts during aerobic heating of the wort. The presence of ethanol makes the spin trapping method more selective and sensitive for the detection of highly reactive radicals such as hydroxyl and alkoxyl radicals. Samples of wort that were collected during the early stages of the mashing process gave higher rates of spin adduct formation than wort samples collected during the later stages. The lower oxidative stability of the early wort samples was confirmed by measuring the rate of oxygen consumption during heating of the wort. The addition of Fe(II) to the wort samples increased the rate of spin adduct formation, whereas the addition of Fe(II) during the mashing had no effect on the oxidative stability of the wort samples. Analysis of the iron content in the sweet wort samples demonstrated that iron added during the mashing had no effect on the iron level in the wort. The moderate temperatures during the early steps of mashing allow the endogenous malt enzymes to be active. The potential antioxidative effects of different redox-active enzymes during mashing were tested by measuring the rate of spin adduct formation in samples of wort. Surprisingly, a high catalase dosage caused a significant, 20% reduction of the initial rate of radical formation, whereas superoxide dismutase had no effect on the oxidation rates. This suggests that hydrogen peroxide and superoxide are not the only intermediates that play a role in the oxidative reactions occurring during aerobic oxidation of sweet wort.
Patent•
31 Jul 2008TL;DR: In this article, a combined brewing system for small scale brewing of fermented alcoholic beverages, particularly beer, and to a method of making fermentation of alcoholic beverages is described, which comprises a single pressurizable vessel.
Abstract: A combined brewing system for small scale brewing of fermented alcoholic beverages, particularly beer, and to a method of making fermented alcoholic beverages. The brewing system comprises a single pressurizable vessel. The beer is naturally carbonated to the desired level during fermentation. Sediment is collected and substantially separated from within the vessel and removed from the vessel while the vessel is under pressure. Compressed gas is added for maintaining natural carbonation levels, so that the contents of the vessel can be drawn off at a desired pressure. The vessel has a temperature control system to selectively control the temperature during processing.
TL;DR: In this paper, the optimal acidification power test (APT) of brewers yeast is performed by storing yeast slurry at 2 oC under beer (AP remains constant for up to 6 days), 15 min sample equilibration to room temperature, decantation and washing by triple normalized centrifugation in deionized water.
Abstract: Optimized acidification power test (APT) of brewers yeast
quality includes storing yeast slurry at 2 oC under beer (AP
remains constant for up to 6 days), 15 min sample equilibration
to room temperature, decantation and washing by triple
centrifugation in deionized water. The final yeast pellet keeps
its AP for up to 6 h at room temperature under water and APT
thus need not be performed immediately after yeast collection.
Correct AP value (maximum acidification produced by given
yeast) is determined at 25, 0.1 oC in 15 ml samples containing
5 % glucose and 1.5 g yeast wet weight. Cell concentration is
conveniently measured as absorbance (A660). Cell flocculation
and/or sedimentation distorting APT results can be prevented by
sample stirring at 200 rpm. The highest AP of yeast cropped
from CCT was exhibited by the middle fractions and postcropping
cooling had no effect on AP. The effect of pitching yeast
vitality on brewery fermentation outcome can be masked by
variations in pitching rate, wort composition, ambient
conditions in the CCT, and other factors.
TL;DR: A relationship has been established that yeast cell wall mannan, an unfilterable haze constituent, is released from the cell wall as a function of G-force and centrifugation cycles, while concurrently, particle sizes between 0.5-2.8 μm and beer haze increased.
Abstract: Hydrodynamic stresses imposed on brewing cells of Saccharomyces cerevisiae during beer processing can have a detrimental impact on beer quality. The use of centrifuges has become an efficient way to increase brewery throughput as they decrease clarification times and improve fermenter and tank conditioning efficiency. The effect of a disc stack centrifuge on yeast and beer physical stability has been investigated. In this study, a commercial ale yeast strain has been subjected to different operating conditions during centrifugation. Cell viability and intracellular pH decreased due to processing conditions encountered during yeast cropping with a centrifuge. A relationship has been established that yeast cell wall mannan, an unfilterable haze constituent, as a function of G-force and centrifugation cycles, is released from the cell wall while concurrently, particle sizes between 0.5-2.8 μm and beer haze increased. Furthermore, yeast intracellular glycogen and trehalose levels were depleted as a result of centrifugation.
1 Feb 2008
TL;DR: In this article, the authors deal with two innovative brewing processes, high gravity batch and complete continuous beer fermentation systems, and show a significant influence of the variables such as concentration and temperature on the yield factor of the substrate into ethanol and consequently on the productivity of the high-gravity batch process.
Abstract: This study deals with two innovative brewing processes, high gravity batch and complete continuous beer fermentation systems. The results show a significant influence of the variables such as concentration and temperature on the yield factor of the substrate into ethanol and consequently on the productivity of the high gravity batch process. The technological feasibility of continuous production of beer based on yeast immobilization on cheap alternative carriers was also demonstrated. The influence of process parameters on fermentation performance and quality of the obtained beers was studied by sensorial analysis. No significant difference in the degree of acceptance between the obtained products and some traditional market brands was found.
Patent•
3 Dec 2008
TL;DR: In this paper, a method for brewing a fruit wine was proposed, which has the advantages that the strain amplification culture solution is subjected to the primary fermentation and the secondary fermentation, therefore the fermentation speed is high, the fermentation time is short, and the fruit wine has good original taste and good stability.
Abstract: The invention discloses a method for brewing a fruit wine The raw materials of the fruit wine comprise the following components by weight percentage: 71wt%-86wt% of fruit crude juice, 9wt%-21wt% of white sand sugar, 4wt%-6wt% of yeast strain amplification culture solution and 1wt%-2wt% of lactobacillus strain amplification culture solution The technological process of the method comprises the steps as follows: (1) juicing fruits, filtering and adding sulfur dioxide (SO2); (2) clarifying the fruit juice; (3) carrying out the primary fermentation; (4) carrying out the secondary fermentation; (5) clarifying the crude wine; (6) blending; (7) carrying out the cold treatment; and (8) sterilizing and canning The method has the advantages that the strain amplification culture solution is subjected to the primary fermentation and the secondary fermentation, therefore, the fermentation speed is high, the fermentation time is short, and the fruit wine has good original taste and good stability; and the bentonite-loaded chitosan is adopted to carry out the clarifying treatment and a diatomite filter is used for filtering, thereby the fruit wine has pure original taste; and the 6-second flash sterilization at the high temperature of 105 DEG C is carried out to prolong the shelf life of the fruit wine
TL;DR: In this article, the authors evaluated the fermentation properties of continuous high gravity brewing with yeast immobilized on spent grains at three different temperatures (7, 10 and 15 °C) and found that the apparent and real degrees of fermentation, rate of extract consumption, ethanol volumetric productivity and consumption of free amino nitrogen (FAN) increased.
Abstract: Flavor compounds’ formation and fermentative parameters of continuous high gravity brewing with yeasts immobilized on spent grains were evaluated at three different temperatures (7, 10 and 15 °C). The assays were performed in a bubble column reactor at constant dilution rate (0.05 h−1) and total gas flow rate (240 ml/min of CO2 and 10 ml/min of air), with high-gravity all-malt wort (15°Plato). The results revealed that as the fermentation temperature was increased from 7 to 15 °C, the apparent and real degrees of fermentation, rate of extract consumption, ethanol volumetric productivity and consumption of free amino nitrogen (FAN) increased. In addition, beer produced at 15 °C presented a higher alcohols to esters ratio (2.2–2.4:1) similar to the optimum values described in the literature. It was thus concluded that primary high-gravity (15°Plato) all-malt wort fermentation by continuous process with yeasts immobilized on spent grains, can be carried out with a good performance at 15 °C.
Journal Article•
TL;DR: O'Connor-Cox et al. as discussed by the authors showed that trehalose can serve as a membrane stabiliser and protectant for yeast cells under stress, and used it as a source of carbon skeletons for biosynthesis.
Abstract: Originally, trehalose was believed to function only as a reserve carbohydrate similar to glycogen. It is now known that the degradation of trehalose yields little energy and whilst it can serve as a source of carbon skeletons for biosynthesis, it mainly functions as a membrane stabiliser and protectant for yeast cells under stress. (O'Connor-Cox et al, 1996). The significance of trehalose as an endogenous protectant is referred to in numerous literature sources.
TL;DR: Based on results, this assay is a useful measure of malt quality as it quantifies the antiyeast activity in malt which may adversely impact on brewery fermentation.
TL;DR: In this article, the water-soluble proteins of two different barley cultivars were investigated by gel electrophoresis and matrix-assisted laser desorption/ionization mass spectrometry.
Abstract: The protein composition of barley partly determines its quality in terms of malting and brewing. For this reason, the water-soluble proteins of two different barley cultivars were investigated by gel electrophoresis and matrix-assisted laser desorption/ionization mass spectrometry. Mass spectra were obtained directly from barley extracts by using three matrices. According to the quality of the measured spectra, it was possible to establish which matrix was the most suitable for the analysis of water-soluble proteins from barley. We found that the protein patterns did not differ significantly between Jersey and Tolar varieties. However, our results showed the influence of the malting process on the posttranslational modification of some water-soluble barley proteins. These proteins also survive the brewing process and they are very important for the formation and stability of beer foam. Several barley proteins were also identified by proteomic analysis.
TL;DR: A brewing yeast mutant with perfect sugar fermentation capacity was isolated by mutagenizing the Saccharomyces pastorianus transformant, which carries an integrated glucoamylase gene and has one copy of non-functional alpha-acetolactate synthase gene, which would be useful for low caloric beer production.
Patent•
25 Jul 2008
TL;DR: A system and method for brewing beverages utilizing inertial separation and an adjustable-volume brewing chamber to selectively retain or release particulate matter, oils, and/or other components of the brewed beverage, whereby mechanical filtration may be avoided and smaller particulates may be separated from the beverage.
Abstract: A system and method for brewing beverages utilizing inertial separation and an adjustable-volume brewing chamber to selectively retain or release particulate matter, oils, and/or other components of the brewed beverage, whereby mechanical filtration may be avoided and smaller particulates may be separated from the beverage. Thus, less material is needed to achieve similar levels of infusion and brewing time may be reduced.
Patent•
18 Aug 2008
TL;DR: In this article, the authors propose to use a stripping element between the stripping element and the collection container to separate the coffee powder cake (17) into pieces (17′, 17″ ) before it reaches the container.
Abstract: A brewing device ( 1 ) for a coffee machine comprises a brewing cylinder ( 6 ) with a cylindrical bore and two pistons ( 3 and 4 ), by means of which the brewing cylinder is able to be closed to form a brewing chamber. The brewing cylinder ( 6 ) and the pistons ( 3 and 4 ) are held in a frame ( 2 ) in a way displaceable relative to each other and are drivable via a drive unit ( 9, 10 ). Before the brewing operation, coffee powder is introduced into the brewing chamber. The coffee powder cake ( 17 ) ejected from the brewing chamber after the brewing operation is able to be stripped off into a collection container ( 20 ) via a stripping element ( 18 ). Disposed between the stripping element ( 18 ) and the collection container ( 20 ) is a subcomponent ( 22 ) that separates the coffee powder cake ( 17 ), stripped off by the stripping element ( 18 ), into pieces ( 17′, 17″ ) before said coffee powder cake reaches the collection container ( 20 ). Achieved thereby is that the coffee powder cakes are able to be temporarily stored in the container ( 20 ) in as space-saving a manner as possible.
Patent•
20 Dec 2008
TL;DR: In this article, a method for the production of beer was proposed, where a gyle was obtained from a mash, the gyle is subsequently subjected to a temperature treatment, the hot sludge was separated from the treated gyle, and beer was obtained after hot trub separation by means of fermentation.
Abstract: The invention relates to a method for the production of beer, wherein a gyle is obtained from a mash, the gyle is subsequently subjected to a temperature treatment, the hot sludge is separated from the treated gyle, and beer is obtained from the gyle after hot trub separation by means of fermentation. For this purpose the invention provides that during the brewing process a particularly aqueous fluid is separately mixed with a hops product and heated to isomerization of the bitterns, and that the fluid pretreated in this manner is subsequently added to the gyle. The invention further provides a device suited for carrying out the disclosed method for the production of beer. A significantly increased hops yield is achieved by means of the separate processing of the hops product as opposed to the prior art.
Patent•
23 Jul 2008
TL;DR: In this paper, the authors presented a complete technology for brewing the high quality soy sauce, where microbial strains (aspergillus oryzae) are added after soy and wheat are dipped in, cleaned, ripened and processed and wine yeast is prepared, then brine is added to prepare crude soy sauce mash that is pressed to extract sauce liquid after a plurality of months of natural fermentation, and the sauce is brewed after concentration, sterilization and filtration.
Abstract: The invention relates to a brewing method of high quality sauce The invention provides a complete technology for brewing the high quality sauce The invention is characterized in that microbial strains (aspergillus oryzae) are added after soy and wheat are dipped in, cleaned, ripened and processed and wine yeast is prepared, then brine is added to prepare crude soy sauce mash that is pressed to extract sauce liquid after a plurality of months of natural fermentation, and the sauce is brewed after concentration, sterilization and filtration The invention solves the defects of sauce brewed by traditional methods and has the advantages of even ripening degree, having no sediment, not being restricted by seasons, short time consumption, low cost, high grain utility rate, stable quality, rich nutrition, long shelf life, low production cost, high economic benefit, lower consumption, saving energy, environmental protection, safe and being sanitary, etc