啤酒活性干酵母在鲜啤酿造中的应用

在鲜啤酒酿造过程中，应用啤酒活性干酵母代替传统啤酒酵母，对比试验结果表明，啤酒活性干酵母具有良好的酿造性能，在鲜啤酿造中应用是可行的。     

浅谈啤酒醇造过程中微生物卫生控制

啤酒已成为大众消费品，素有“流体面包”的美称。现在越来受人们的喜爱和青睐。啤酒主要是通过酵母酿造发酵而成。整个酿造生产过程受到严格的微生物卫生控制，若酿造生产的某个环节把关控制不当，就会造成啤酒酿造过程的污染菌，使发酵出现异常情况，这样不仅影响啤酒质量，而且给厂家造成一定的经济损失，因此，对酿造中的微生物卫生必须做到严格控制。     

报类文摘

生产低酒精啤酒许多啤酒厂已选择了一种被称为低酒精（LA）的啤酒或无酒精啤酒，当然，通过调节供给酵母细胞的糖量，对于酿造出低酒精度啤酒的工艺是容易的，但是酿造无酒精度的啤酒却很难。最近，加拿大一家酿造啤酒厂试验性地销售含0.5％的酒精度的啤酒，并出售含5％酒精度的啤酒，其结果，许多品尝者辩别不出两种啤酒的不同。酿造低酒精度啤酒的奥秘是采用大量的酵母（有时比普通方法高出30倍）。在低温下通过二氧化碳使酵母浮在麦芽汁中，酵母在低温下代谢时只能将很少一部分糖转化成酒精，但酿造出的低酒精度啤酒仍然保持典型啤酒的…     

啤酒工业的原辅材料与啤酒酿造质量

啤酒工业的原辅材料是指参与啤酒酿造过程和形成最终产品的所有物料的总称，包括酿造用水、大麦芽、啤酒花、纯种酵母和淀粉质辅料，也包括一些添加剂和加工助剂。这些材料的选择与使用，不仅影响整个啤酒加工过程，而且影响最终啤酒产品的质量。本文讨论的重点是酿造用水、大麦芽、啤酒花与啤酒酿造质量的关系。     

酿造水中的"三氮"化合物对啤酒酿造的影响——酿造水中的氨态氮对啤酒酿造的影响(一)

概述： 水是酿造啤酒所用的“四大”原料中用量最多的原料，同时也是啤酒组成中含量最高的组分（超过90％），因此有“水是啤酒血液”之美称。水对啤酒酿造的重要性与复杂性是因为啤酒酿造中所用的水不是化学上的水（即不是纯水），而是溶解有多种成分的水溶液，而在这些成分中，更多的只能是定性而不能定量，正因为存在这么多的未知，才导致酿造水对啤酒酿造影响的复杂性、不确定性和很难的预见性。随着人类活动的增加，加重了水的污染，而这种污染对啤酒酿造会产生不利的影响而不会产生好的影响。     

提高啤酒抗氧化能力保证啤酒质量

氧对啤酒的危害众所周知。本文从啤酒酿造、包装过程的多个环节入手，总结了啤酒生产中防止或减少氧化，提高啤酒抗氧化能力的一些措施，为啤酒酿造者提供一些参考。     

培养基对检测啤酒厌氧菌的影响

啤酒酿造过程中厌氧菌的控制越来越受到酿造师的重视，不同培养基对啤酒厌氧菌有不同的敏感性，啤酒生产中可以选择不同培养基来培养啤酒厌氧菌，以加强质量控制。     

高浓酿造技术在啤酒工业中的应用

高浓酿造技术在啤酒工业中的应用越来越广泛，其主要特点是在不增加设备的基础上能大幅度提高产量，对高浓酿造技术在啤酒工业中的应用进行了较为详细的论述，总结了高浓酿造的特点、高浓麦汁的制备、啤酒酿造糖浆的选择等。最后，讨论了高浓酿造技术对酿造工艺过程、啤酒酵母及最终产品的影响。     

浅论啤酒酿造用水的水质

水是啤酒酿造中使用最多的原料，酿造水被称之为“啤酒的血液”。世界著名啤酒的特色都是由各自酿造用水的水质所决定的，酿造用水不仅直接影响着酿造的全过程，而且还决定着产品的质量和风味。水中含有一定量的各种阳离子和阴离子，这些离子对糖化过程酶的作用、物质的转化、麦汁的组成、发酵过程以及啤酒的质量产生特有的影响。[第一段]     

美国手工精酿啤酒来到中国

在过去的10年间，手工精酿啤酒在美国成为发展速度最快的酒精类饮品。 美国手工精酿啤酒的酿造商规模较小，形式独立，酿造传统风味的啤酒。美国手工精酿啤酒一般采用传统成分酿成，如大麦麦芽，啤酒花，酵母和水。经常，酿造商也会加入创新的，有时甚至是非传统的成分，以体现啤酒的独特性。     

Screening for new brewing yeasts in the non‐Saccharomyces sector with Torulaspora delbrueckii as model

This study describes a screening system for future brewing yeasts focusing on non‐Saccharomyces yeasts. The aim was to find new yeast strains that can ferment beer wort into a respectable beer. Ten Torulaspora delbrueckii strains were put through the screening system, which included sugar utilization tests, hop resistance tests, ethanol resistance tests, polymerase chain reaction fingerprinting, propagation tests, amino acid catabolism and anabolism, phenolic off‐flavour tests and trial fermentations. Trial fermentations were analysed for extract reduction, pH drop, yeast concentration in bulk fluid and fermentation by‐products. All investigated strains were able to partly ferment wort sugars and showed high tolerance to hop compounds and ethanol. One of the investigated yeast strains fermented all the wort sugars and produced a respectable fruity flavour and a beer of average ethanol content with a high volatile flavour compound concentration. Two other strains could possibly be used for pre‐fermentation as a bio‐flavouring agent for beers that have been post‐fermented by Saccharomyces strains as a consequence of their low sugar utilization but good flavour‐forming properties. Copyright © 2015 John Wiley & Sons, Ltd.     

The Contribution of Geraniol Metabolism to the Citrus Flavour of Beer: Synergy of Geraniol and β‐Citronellol Under Coexistence with Excess Linalool

The behaviour of hop‐derived monoterpene alcohols during fermentation by lager yeast was previously investigated in this laboratory. It was suggested that the concentration of geraniol and β‐citronellol in the finished beer increased depending on the initial concentration of geraniol in the wort. In addition, an additive effect among linalool, geraniol and β‐citronellol was found and 5 ug/L of geraniol and β‐citronellol was enough for this effect. In this paper, conditions regarding the enrichment of the initial concentration of geraniol in the wort were investigated. From the screening of various hop cultivars, Citra hop was selected as a geraniol‐rich cultivar. In addition, it was observed that coriander seed, which can be used in beer production as a flavourant, contained not only linalool but also geraniol at high levels. The use of Citra hop or coriander seed was effective for enriching the concentration of geraniol and β‐citronellol in the finished beers. In the Citra beer and in the coriander beer, the content of linalool was excess in comparison with the content of geraniol and β‐citronellol. Therefore, the synergy of geraniol and β‐citronellol, under coexistence of excess linalool, was examined. It was found that the flavour impression of excess linalool became more fruity and citrus by coexistence with geraniol and β‐citronellol and that the coexistence of all three monoterpene alcohols was effective for this synergy. The flavour characteristics of the Citra and coriander beer and the importance of geraniol metabolism for a citrus flavour in beer are discussed.     

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     

Processing of a Top Fermented Beer Brewed from 100% Buckwheat Malt with Sensory and Analytical Characterisation

A top fermented beer was brewed from 100% buckwheat malt and sensory and analytical characterisation was carried out. Difficulties with lautering and filtration were encountered during the brewing process, which resulted in problems during fermentation and beer filtration. The beer was evaluated in the fresh and forced aged state for the following attributes: odour, purity of taste, mouthfeel, tingling, and bitterness. Analytical results indicated that the buckwheat beer compared quite closely to a typical wheat beer with regard to pH, FAN, fermentability and total alcohol. However, the extract of the buckwheat wort was lower, resulting in a final extract yield of 54.5%. GC analysis of the resultant beer revealed commonly encountered levels of the esters that give beer a fruity character. A low level of fusel alcohols, in comparison to a typical wheat beer, was detected. A high level of ethyl caprinate (coconut flavour) and lauric acid (fatty odour) was detected. Sensory analysis indicated that the buckwheat beer was acceptable with regard to odour, purity of taste, mouthfeel, tingling and bitterness. In conclusion, results of this study prove buckwheat's qualification as a gluten‐free brewing material and with process optimisation, its readiness for marketing.     

Production of alcohol‐free beer with elevated amounts of flavouring compounds using lager yeast mutants

Arrested or limited fermentation process is a widespread method used for production of alcohol‐free beer (AFB). However, it usually leads to worty off‐flavour and a lack of pleasant fruity flavour/aroma. The aim of this study was to isolate spontaneous mutants of Saccharomyces pastorianus strain 2 resistant to 5,5,5‐trifluoro‐dl ‐leucine, since the resistance is related to overproduction of flavour active isoamyl alcohol (IAAL) and isoamyl acetate (IAAC). The mutants were the subject of selection during series of screening tests aimed at selecting the best producer of target compounds (IAAL and IAAC). Subsequently, the overproduction stability of the selected mutant strain was verified in four consecutive fermentations of AFBs. A higher pitching rate and increased fermentation temperature did not result in an overall improvement in the production of the target compounds. Sensory analysis proved the flavouring effect of the spontaneous lager yeast mutant on the AFB produced by arrested fermentation. Copyright © 2013 The Institute of Brewing & Distilling     

INFLUENCE OF pH ON FLAVOUR STALING DURING BEER STORAGE

A decreasing pH accelerated an increase in the chemiluminescence production and degradation of isohumulones and procyanidins during the storage of beer and using a model system. The sensory test showed that the addition of HCI to fresh beer accelerated the flavour staling during beer storage but that the addition of HCI to stored beer did not significantly accelerate the flavour staling. Therefore, it was thought that the acceleration of beer flavour staling is not dependent on a decrease in pH such that the decreasing pH isolates stale flavour aldehydes by a dissociation from staling-flavour aldehyde adducts but based on the fact that the decreasing pH accelerates the flavour staling reactions, free radical reactions, during beer storage.     

常见啤酒风味病害产生原因及预防

啤酒风味的病害原因有：原料、工艺带来的口味粗涩、后苦味;高级醇形成的腻厚味;酵母自溶产生的酵母味;双乙酰、乙醛等含量同产生的不成熟味;贮存中产生的氧化味,代谢产物的酸味;原料麦皮味;日光臭味;发酵器具的涂料味;铁腥味;啤酒酸味等。针对各原因,采取用优质酒花,正确添加酒花等对症下药的解决办法和防控措施,可提高啤酒产量,生产优质啤酒。     

Analysis of flavour compounds in beer with extruded sorghum as an adjunct using headspace solid‐phase micro‐extraction and gas chromatography–mass spectrometry

Sorghum is a widely used adjunct that is used in the production of beer and increasingly affects beer flavour as the amount added increases. The aim of this work was to establish a simple, solvent‐free technique, without derivatization, to analyse flavours and typical volatile compounds present in extruded and unextruded sorghum beer, and to compare the flavour differences of the two types of beer. Headspace solid‐phase micro‐extraction gas chromatography–mass spectrometry was used to determine the flavours in the two beers and eight typical volatile compounds were quantified using GC. Forty‐five flavour compounds were identified and quantified in extruded white sorghum beer, while 31 flavour compounds were identified in unextruded white sorghum beer. Extruded or unextruded white sorghum can be used to produce ale beer, but the primary flavour content in the extruded white sorghum beer was higher than in the unextruded white sorghum beer. Copyright © 2016 The Institute of Brewing & Distilling     

THE FLAVOUR OF BEER—A REVIEW*

Following a general consideration of the chemical nature of compounds which provide sensations of taste or of odour, the flavour components of beer are discussed in some detail. Methods suitable for determining individual flavour compounds are indicated in relation to organoleptic assessment by a selective panel of testers. The concept of “flavour index” (flavour threshold of a component divided by the concentration of that component in beer) is introduced: substances with a low flavour index require close control in the production of beer.