啤酒花的化学研究及其和啤酒酿造的关系

啤酒花用于啤酒酿造,在增加啤酒苦味的同时可改善啤酒的风味和提高啤酒的泡沫稳定性。随着化学分离和鉴定技术的不断完善,使得可以通过调整使用啤酒花的不同种类和数量来改进啤酒质量。啤酒花中主要化合物对啤酒质量可产生重要的影响,其中,树脂类化舍物,主要是α-酸和β-酸类,可赋予啤酒独特的苦味特征;精油类成分使啤酒具有明显的香味特征;而啤酒花中的多酚可对啤酒的风味及其风味稳定性产生重要的影响。     

THE INSTITUTE OF BREWING ANALYSIS COMMITTEE THE BREWING VALUE OF OLD HOPS. RELATIONSHIPS BETWEEN ANALYSES AND FLAVOUR

Beers were brewed with old and new hops and the relationships were studied between methods for estimating α-acids, beer bitterness and beer flavour. It was concluded that the α-acid content of hops at harvest is a simple and reasonably reliable guide to the brewing value of old hops; that the beer bitterness determined analytically is a good guide to that tasted; that beers brewed with old and new hops will differ little in bitter or harsh taste if the analytical bitterness levels are similar; and that tasters can distinguish between bitterness levels of 5 E.B.C. units at values around 30 units.     

Effect of bacteriocin‐producing Pediococcus acidilactici K10 on beer fermentation

Beer is generally considered to be a beverage that has high microbiological stability. However, some undesirable lactic acid bacteria (LAB) can grow in beer and consequently spoil this beverage. In this study, bacteriocin‐producing Pediococcus acidilactici K10 was used as a means of bio‐acidifying the mash and reducing the spoilage LAB content of the beer. The K10 strain had antimicrobial activity against two beer spoilage LAB strains in wort and did not grow in a beer environment. The K10 strain was inoculated before the mashing step. The effect of K10 as a starter culture was investigated and compared with a control. As a result, filtration time was shortened by 17 min, alcohol content was increased by 137%, foam stability was increased by 156%, bitterness was increased by two bitterness units and there was a significant difference (p < 0.05) in aromatic and sour odour. The feasibility of using bacteriocin‐producing LAB strain in beer brewing is envisaged. Copyright © 2016 The Institute of Brewing & Distilling     

Measurement of Human Brain Activity Evoked by Stimulation of Beer Bitterness Using Magnetoencephalography

ABSTRACT: We tried to detect the human brain activity evoked by beer taste using magnetoencephalography Subjects did not perceive bitterness and tactile stimulus differences between water and commercial beer, through a small hole of the taste stimulator, but they perceived bitterness for the beer enriched with isohumulones. The increase in the magnetic fields after the stimulation onset was observed for the stimulus of the beer with addition of isohumulones but was not observed for the stimulus of water or commercial beer, supporting the subject's comments. In 76.2% of the all measurements for the beer enriched with isohumulones, the equivalent current dipoles, placed on a subject's 3-dimensional magnetic resonance imaging, were located at the transition between the parietal operculum and the insular cortex with latency at 326.7 ± 115.5 ms. These results indicated that the brain activity stimulated by beer bitterness could be detected.     

Use of Response Surface Methodology to Investigate the Effectiveness of Commercial Enzymes on Buckwheat Malt for Brewing Purposes

The influence of two factors, total concentration and fraction of three pairs of commercial enzymes, which showed statistical significance (Biocellulase W with Hitempase 2XL, Biocellulase W with Amylo 300 and Amylo 300 with Hitempase 2XL), were studied for their overall effect on buckwheat wort quality using response surface methodology (RSM). This study revealed that the addition of increasing levels of Hitempase 2XL to the buckwheat mash increased colour, extract levels, wort filtration, fermentability and total fermentable extract (TFE), along with decreasing viscosity values. Results also determined a high level of fermentability when an enzyme combination of 30% Biocellulase and 70% Hitempase was added to the mash. The addition of increasing levels of Amylo 300 to buckwheat mashes resulted in increases in fermentability and total fermentable extract (TFE), along with increases in total soluble nitrogen (TSN), free amino nitrogen (FAN) and Kolbach index (KI). With regard to the proposed optimal regime, although no synergistic effect was found when the three enzymes were used together, the optimum conditions for the production of buckwheat wort with lowest viscosity, highest extract and optimal fermentability were achieved using a joint model. Overall, the findings of this study demonstrate the feasibility of producing wort suitable for the brewing of gluten‐free beer from 100% malted buckwheat with careful optimisation of enzyme types and dosage levels.     

啤酒溶解氧控制的研究

啤酒中过量溶解氧的存在,易发生老化、氧化作用,使啤酒出现老化味,降低其风味稳定性.溶解氧过量对啤酒产生的危害主要有:①促使啤酒胶体浑浊;②促使多酚物质氧化、聚合;③使连二酮回升;④破坏酒花的香味和苦味;⑤产生老化味等.控制啤酒中的溶解氧的主要措施:①在下酒、贮酒及过滤过程中,加强对管路的巡视;②在下酒过程中,排除贮酒罐中的空气;③避免过滤机排气不彻底;④提高CO2纯度,以最大限度地减少对啤酒溶解氧的影响.     

The multisensory perception of hop essential oil: a review

Hops are a key ingredient to add bitterness, aroma and flavour to beer, one of the most consumed beverages worldwide. Essential oils from different hop varieties are characterised by similar classes of chemical compounds and complexity, but their contribution to sensory characteristics in beer differs considerably. Volatiles in hop oil are categorised into several chemical classes. These induce diverse aroma and flavour sensations in beer being described as ‘floral’, ‘fruity’ (e.g. contributed by alcohols, esters, sulphur-containing compounds), ‘spicy’, ‘woody’, ‘herbal’ (sesquiterpenes, oxygenated sesquiterpenoids), and ‘green’ (aldehydes). The perception of hop volatiles depends on their concentrations and combinations, but also on threshold levels in different beer matrices or model systems. Several studies attributed modified taste and mouthfeel sensations to the presence of hop volatiles contributing to a multisensory perception of hop flavour. Linalool is frequently observed to show additive and synergistic-type behaviour and to affect aroma perception if combined with geraniol. Linalool has also been found to be involved in aroma-taste interactions, modifying the perception of bitterness qualities in beer. Particularly oxygenated sesquiterpenoids are suggested to be responsible for an irritating, tingling sensation indicating the activation of trigeminal receptors. The majority of these sensory interactions have been discovered almost by accident and a systematic research approach is required to gain a broad understanding of these complex phenomena. This review provides an overview of factors affecting the perception of hop derived volatiles involved in different sensory characteristics of beer, while illustrating the latest advances and highlighting research gaps from a sensory science perspective. © 2020 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling     

啤酒酵母抽提物工业化生产

据统计，每生产1t啤酒就有1.5kg啤酒废酵母（干）产生，一个年产10万t的啤酒企业可产生150t啤酒废酵母，可实现工业化生产。经过多次工业试验，酵母抽提物得率可达70％。生产工艺为酵母泥经除杂、压榨取酒、水洗脱苦、调浆、自溶（酶解）、灭酶、过滤、滤液浓缩、调配而得成品。生产10万t的啤酒企业，其啤酒酵母用于生产酵母抽提物，可创造效益近200万元。同时，还产生明显的社会效益和环保效益。（庞晓）     

低浓度淡爽型啤酒的酿造

以改善低浓度淡爽型啤酒品质为目的 ,提出了一种新颖的低浓度淡爽型啤酒的酿造方法 .采用二次煮出二段式糖化法 ,用 70 %麦芽和 3 0 %大米的原料配比 ,提高麦芽汁中糖与非糖的比值 ,并在糖化过程中添加啤酒酵母提取物作啤酒发酵的补充氮源 .所酿造的啤酒口味纯正 ,泡沫洁白细腻 ,持久挂杯 .     

影响啤酒过滤性能的酶制剂

总结了整个啤酒酿造过程中各个工艺因素对啤酒过滤的影响，并提出相应的工艺控制措施，特别侧重于各项新技术、新工艺（如用低发芽率麦芽、小麦芽酿酒、露天罐技术及酒龄缩短等）采用后给啤酒过滤造成不利影响的情况下，采取相应的工艺措施来提高啤酒的过滤性能。     

以小麦面粉作为辅料生产小麦啤酒

研究小麦面粉作为啤酒辅料酿造工艺,在小麦面粉的最大添加量占原料的20%的条件下,中性蛋白酶添加量0.10 mL/kg,耐热α-淀粉酶添加量20 u/g,木聚糖酶的添加量1.8 mL/kg,解决小麦面粉作为啤酒辅料中出现黏度大,过滤困难等不利因素;同时采用上面发酵工艺,以其他辅料酿造啤酒的麦汁和发酵液的理化指标为参照,进一步评估工艺的合理性;研究利用蛋白疏水层析色谱法(HIC),对添加小麦面粉作为辅料生产的小麦啤酒的啤酒泡沫中分离疏水蛋白,其疏水蛋白含量显著增加,并显著提高啤酒的泡沫性能。同时酿造的啤酒具有典型的小麦啤酒的特征香味4-乙烯基愈创木酚味道。     

Modification of perceived beer bitterness intensity,character and temporal profile by hop aroma extract

The effect of hop aroma on perceived bitterness intensity, character and temporal profile of beer was investigated. A hop aroma extract was added at 3 levels (0, 245, 490 mg/L) to beers at low, medium and high bitterness. Beers were evaluated for perceived bitterness intensity, harshness, roundedness and linger by a trained panel using a rank-rating technique at each bitterness level, with and without nose clips. The use of nose clips enabled the olfactory aspect to be decoupled from taste and mouthfeel aspects of bitterness perception. Results showed significant modification of perceived bitterness in beer by hop aroma depending on the inherent level of bitterness. These modifications were mainly driven by olfaction – in an example of taste-aroma interactions, as well as certain tactile sensations elicited by the hop aroma extract in the oral cavity. At low bitterness, beers with hop aroma added were perceived as more bitter, and of ‘rounded’ bitterness character relative to those without hop aroma. When judges used nose clips, this effect was completely eliminated but the sample was perceived to have a ‘harsh’ bitterness character. Conversely, at high bitterness, even when nose clips were used, judges still perceived beers containing hop aroma to be more bitter. These increases in bitterness perception with nose clips indicates the stimulating of other receptors, e.g. trigeminal receptors by hop aroma extract, which in tandem with the high bitterness, cause perceptual interactions enhancing bitterness intensity and also affecting bitterness character. Bitterness character attributes such as ‘round’ and ‘harsh’ were found to significantly depend on bitterness and aroma levels, with the second level of aroma addition (245 mg/L) giving a ‘rounded’ bitterness in low bitterness beers but ‘harsh’ bitterness in high bitterness beers. The impact of aroma on temporal bitterness was also confirmed with time-intensity measurements, and found to be mostly significant at the highest level of hop aroma addition (490 mg/L) in low bitterness beers. These findings represent a significant step forward in terms of understanding bitterness flavour perception and the wider impact of hop compounds on sensory perception.     

Comparison of beer quality attributes between beers brewed with 100% barley malt and 100% barley raw material

BACKGROUND: Brewing with 100% barley using the Ondea^® Pro exogenous brewing enzyme product was compared to brewing with 100% barley. The use of barley, rather than malt, in the brewing process and the consequences for selected beer quality attributes (foam formation, colloidal stability and filterability, sensory differences, protein content and composition) was considered. RESULTS: The quality attributes of barley, malt, kettle‐full‐wort, cold wort, unfiltered beer and filtered beer were assessed. A particular focus was given to monitoring changes in the barley protein composition during the brewing process and how the exogenous OndeaPro^® enzymes influenced wort protein composition. All analyses were based on standard brewing methods described in ASBC, EBC or MEBAK. To monitor the protein changes two‐dimensional polyacrylamide gel electrophoresis was used. CONCLUSION: It was shown that by brewing beer with 100% barley and an appropriate addition of exogenous Ondea^® Pro enzymes it was possible to efficiently brew beer of a satisfactory quality. The production of beers brewed with 100% barley resulted in good process efficiency (lautering and filtration) and to a final product whose sensory quality was described as light, with little body and mouthfeel, very good foam stability and similar organoleptic qualities compared to conventional malt beer. In spite of the sensory evaluation differences could still be seen in protein content and composition. Copyright © 2011 Society of Chemical Industry     

浅谈四氢异构酒花浸膏在啤酒酿造中的应用

四氢异构酒花浸膏对啤酒有良好的光稳定性，与疏水性蛋白质结合，可增加啤酒的泡沫性能；可赋予啤酒纯正的苦味，增加啤酒的口感；降低啤酒的日光臭味；增加啤酒的非生物稳定性。用蒸馏水或去离子水将四氢异构酒花浸膏稀释10倍后用，添加量为浓度为5％四氢异构浸膏50ml/kl啤酒。（孙悟）     

Multivariate analysis for feasibility of Korean six‐row barleys for beer brewing

The feasibility of using six‐row barley, which is produced more often than two‐row barley (malting barley) in Korea, for beer brewing was studied. Beer was brewed from one variety of two‐row barley (Jinyang, malting barley) and four varieties of six‐row barley (Jasujungchal and Hinchalssal which are unhulled; Dahyang and Samgwangchal which are hulled). Using principal component analysis of the material properties in malting, mashing and fermentation, and the sensory properties of beer, the barley was categorized into three groups: group 1 (Jinyang and Dahyang), group 2 (Samgwangchal and Hinchalssal) and group 3 (Jasujungchal). Group 1 was distinctive for extract (dry basis), Brix and carbonation; group 2 was characterized by alcohol, foam stability and sour odour; and group 3 was characterized by malt protein and sour taste. The brewing qualities of group 1 were superior to those of the other groups. Among the Korean six‐row barley varieties, Dahyang was found to be the most suitable for beer production. Copyright © 2014 The Institute of Brewing & Distilling     

Pilot Scale Production of a Lager Beer from a Grist Containing 50% Unmalted Sorghum

Pilot scale (1000 L) brews were carried out with a grist comprising of unmalted sorghum (50% of total wet weight of grain) (South African variety) and malted barley (50% of total wet weight of grain) grist using a mashing program with rests at 50°C, 95°C and 60°C. Mashes were supplemented with a high heat stable bacterial α‐amylase, a bacterial neutral protease and a fungal α‐amylase. A control brew containing 100% malted barley was also carried out. Saccharification difficulties were encountered during mashing, and extraction of the grist was lower for the sorghum mashes. The sorghum mashes showed comparable lautering behaviour to that of the control mash. At mashing off the sorghum worts were starch positive. Apparent degree of fermentation of the sorghum gyles were less than the control gyles. Green beer filtration proved unproblematic. The sorghum beers compared quite closely with the control beer with regard to colour, pH and colloidal stability. Foam stability deficiencies were apparent with the sorghum beer. However, the fermentability of the sorghum worts were lower. Hence the sorghum beers were lower in total alcohol. Sensory analysis indicated that no significant differences existed between the sorghum beer and both the control beer and a commercial malted barley beer with regard to aroma, mouth‐feel, after‐taste and clarity. However, the sorghum beer was found to be significantly different to both of the other beers with regard to colour, initial taste and foam stability.     

“SP-3”与“SP-2”在全小麦啤酒酿造中应用研究

“SP-3”是新选育的啤酒酵母菌株,而“SP-2”为通常生产大麦芽啤酒使用的啤酒酵母菌株,“SP-3”与“SP-2”啤酒酵母菌株在全小麦啤酒生产中应用对比试验结果表明,“SP-3”啤酒酵母菌株在全小麦芽啤酒的酿造中适用性较强,各项指标均优于“SP-2”啤酒酵母菌株,用其酿制的啤酒口感纯正、清爽、柔和,能够较好地适应当前消费者的口感需求.     

高纯食品鞣酸在啤酒中的应用

在啤酒的生产过程中添加高纯食品鞣酸可除去啤酒中的敏感蛋白、金属离子和多酚物质，可降低啤酒的浊度,提高啤酒的胶体稳定性，延长啤酒的保质期。实验表明。在过滤时加入鞣酸最好。最佳添加量为20mg／L。鞣酸为提高啤酒非生物和风味稳定性最好的稳定剂。(孙悟)     

A study of beer bitterness loss during the various stages of the Romanian beer production process

Beer is one of the oldest known alcoholic beverages produced by a yeast fermentation of a cereal extract that was germinated in water beforehand. The bitter taste of beer comes from the group of substances introduced during wort boiling, which are the extracted components of hops. The aim of this study was to determine some characteristics of beer (original extract, alcohol content, colour, pH, total acidity, carbon dioxide and bitterness values) during the three stages of the beer production process in a typical Romanian brewery. Measurements were carried out on 60 samples of beers, 10 measurements for each step of the process examining wort, unfiltered fermented beer and bottled beer (final product) from two different types of beer (light and dark). Statistical process control of the beer was performed. Losses in the bitterness units during the production process were between 24.7 and 41.54%, reported in terms of final product. Copyright © 2013 The Institute of Brewing & Distilling