啤酒酿造中提高啤酒辅料用量的工艺研究

研究了在啤酒酿造过程中，利用酵母浸出液补充糖化麦汁氮源来提高辅料用量的啤酒酿造技术。     

啤酒酿造中提高啤酒辅料用量的工艺研究

研究了在啤酒酿造过程中，利用酵母浸出液补充糖化麦汁氮源来提高辅料用量的啤酒酿造技术。     

高浓发酵和酸洗对酿造酵母的影响

用磷酸类杀菌物质来洗涤接种酵母，以避免细菌污染是许多啤酒厂通用的方法，使用不正确的方法洗涤酵母将使其发酵特性下降并产生不良影响。酵母酸洗后接种于１２Ｐ麦汁，发酵特性没有明显下降；而接种于２０Ｐ麦汁，在发酵的第一个２４小时，酵母的活力就有所下降，但酵母的发酵特性没有变化。     

应用一种新开发的方法评价麦芽对酵母过早絮凝的影响

酵母过早絮凝（PYF）是酿造工业中一个严重的问题。在酵母发酵时还存在较高糖浓度时就发生了酵母絮凝，会造成酵母细胞数的太幅下降，影响啤酒质量。了解麦芽的PYF潜力对于酿酒师来说是非常重要的。我们开发一种两天发酵的方法来评价麦芽的PYF潜力，使用酿造回收酵母或扩培Lager酵母进行50mL规模的试验。这种方法对于批次采购的麦芽以及酿造配比时的效果评价非常有效。这种新开发的方法是研究PYF很好的工具，我们总结了以下几点①长期贮存的麦芽对降低PYF潜力无作用；②对未粉碎麦芽进行清洗对降低PYF潜力有效；③PYF阳性麦芽对所有的aIe酵母影响不明显；④所有的lager酵母对PYF麦芽敏感。甚至即使是非絮凝的.     

不同接种顺序条件下3株酵母属菌株生长及酿造特性研究

为研究不同接种顺序条件下酵母属（Saccharomyces sp.）菌株混菌发酵时的生长变化及酿造特性，以分离自浓香型白酒糟醅中的酿酒酵母（Saccharomyces cerevisiae）Y134、卡斯泰利芽殖酵母（Saccharomyces castellii）Y141和单孢酵母（Saccharomyces unisporus）Y140为研究对象，考察接种顺序对3株菌在五粮粉糖化液中发酵时的生长状态、理化指标以及挥发性风味物质的影响。结果表明，同时接种时菌株Y134占绝对优势，菌株Y141对菌株Y140有一定程度的抑制作用；顺序接种时菌株Y134的竞争优势明显减弱，菌株Y141和菌株Y140降低了菌株Y134的最大活菌数，菌株Y141失去对菌株Y140的抑制作用。接种顺序对五粮粉糖化液的pH无明显影响，而顺序接种会延迟菌株Y134混合培养时对还原糖的利用，降低菌株产乙醇能力，提高乙酸乙酯、异丁醇和异戊醇含量，说明顺序接种不利于此3株Saccharomyces sp.酵母菌更好的发酵五粮粉糖化液。     

小米黄酒酿造工艺的研究

通过单因素和正交试验,优选出小米黄酒的最佳糖化和发酵工艺条件.结果表明:加曲量1.0 g/kg,糖化温度30℃,糖化时间72 h为最优的糖化条件;酵母添加量0.32 g/kg,发酵温度35℃,发酵时间8d为最优的发酵条件.     

锌离子在啤酒酿造中的作用与控制

啤酒中锌离子来源于麦芽、大米、酿造用水、酒花。Zn^2 在啤酒酿造过程中可起到催化荆作用，与氨基酸结合形成Zn-氨基酸螯合物。在啤酒酿造过程中，可激活酶提高酶的作用；促进糖化、发酵；促进蛋白质合成及其稳定性；缓解某金属离子的毒性作用，促进挥发物质的产生和双乙酰的还原，缩短发酵时间，提高啤酒质量；但含量过量会使啤酒非生物稳定性降低，影响啤酒质量。通过对糖化过程和发酵过程的控制，可降低醪液pH值。加入少量小麦芽，加入适量ZnCl2，ZnSO4及酵母营养盐等，可实现对Zn^2 的有效控制，达到最佳酿造浓度。     

增进淀粉水解作用的扩散糖化工艺

<正> 在啤酒酿造中,须先把麦芽磨碎成理想的淀粉颗粒,再经糖化水解,酶才能将淀粉转化成可发酵的浸出物。然而,就已知的天然淀粉组分来说,特别是麦芽尖端中的淀粉,以及那些包囊在细胞壁内的淀粉,一般的糖化水解技术很难对之进行水解,或只能完成部分水解。对于这些没有被水解或没有被充分水解的淀粉粒子,酶不能把它们转化成细小的、可由酵母进行发酵的糖分子、从而降低了浸出物的产率。扩散糖化工艺能对天然淀粉颗粒进行均质水解作用,提高酶的作用和产率,降低了啤酒的生产成本,是一种理想的糖化技术。     

用清酒技术酿造醇清黄酒的试验研究

用日本清酒技术酿造醇清黄酒生产试验，原料选用中，晚熟粳米，制曲以糙米为原料，用传统的曲盒法生产，酵母为醇2号纯种酵母，发酵投料分初投，二投，三投，成熟醑经压滤，61－62℃灭菌2－3min，再调质得15．5度的醇清黄酒.(孙悟）     

使用高温回收酵母结合酵母酸洗降低发酵液厌氧菌数

本文介绍了我公司在生产中高温回收酵母，达到降低发酵液厌氧菌数的目的，并就采用高温回收酵母的发酵液进行了酵母数、酵母死亡率、双乙酰变化、降糖及α-氨基氮同化率等一系列分析。     

筛选啤酒酵母的标准培养基研究

通过以大生产麦汁成分的含量作为参考,如氨基酸的种类、含量,各种可发酵性糖的种类、含量,以及通过查阅大量文献资料了解酵母培养所需的一些必需组分,以此为基础,研制标准培养基的配料单,并结合与大生产麦汁做发酵性能测试,测试指标包括降糖速度、风味组分、还原双乙酰等指标,最终确定合理的配方;并验证其发酵性能的稳定与重复性;试验结果表明,配制培养基与大生产麦汁的各项发酵性能与指标接近,而且具有较好的重复与稳定性。可以用于酵母筛选,从而确定筛选优良酵母菌种的客观性。     

SOME REASONS WHY HIGH GRAVITY BREWING HAS A NEGATIVE EFFECT ON HEAD RETENTION*

Our aim was to examine the effect of high gravity brewing on head retention with respect particularly to the effect of high gravity brewing on hydrophobic polypeptide levels. High gravity brewed beer had poorer head retention values when compared to a similarly brewed low gravity beer. Analysis of hydrophobic polypeptide levels in both high gravity wort (20° Plato) and low gravity wort (10° Plato) produced using a lauter tun, revealed that the high gravity wort contained 8% less hydrophobic polypeptide than the low gravity wort (undiluted basis). Analysis of hydrophobic polypeptides throughout the brewing process for these 10°P and 20°P brews demonstrated that the hydrophobic polypeptide content decreased, especially during the kettle boil and fermentation. Furthermore, the high gravity brewed beer suffered the greatest loss, leaving the final beer with approximately 40% less hydrophobic polypeptides than the low gravity beer. Brewing at 10°P and 20°P using a mash filter demonstrated that these filters can improve the head formation and stability of the resultant beers at sales gravity. However, the low gravity beer still produced a more stable foam (Rudin value 93 s) when compared to the high gravity beer (Rudin value 83 s). The mash filter slightly increased the hydrophobic polypeptide extraction. It is concluded that the mash filter produced higher hydrophobic polypeptide levels in the final beers, as well as having a positive effect on reducing the levels of foam negative compounds such as fatty acids in the wort, and therefore slightly improved head retention values .     

异构酒花颗粒在啤酒酿造中的应用研究

对异构酒花颗粒和普通酒花颗粒进行了对比研究。结果表明,添加异构酒花颗粒可减少苦味物质的损失,酿造出的啤酒优于只采用普通酒花颗粒酿造出的啤酒,特别是酒花香突出,泡特性好。     

Wort composition and its impact on the flavour‐active higher alcohol and ester formation of beer – a review

The most significant factors influencing beer quality are the variety of aroma flavours that stem from a complex system of interactions between many hundreds of compounds. With increasing demand for flavour control and enhanced productivity, the presence of consistent and balanced amounts of higher alcohols and esters are critical aspects of process control. Extensive research has focused on the formation of flavour compounds by the brewing yeast and the factors that influence their synthesis. Fermenting wort is a complex medium from which the brewing yeast utilizes nutrients for living and growth and to where it places its metabolic by‐products. Thus, changes in wort composition will greatly influence final beer aroma. The current paper reviews up‐to‐date knowledge on the contribution of wort composition to the flavour quality of the final product, in particular higher alcohols and esters. Different wort constituents involved in the biosynthesis of these aromatic substances, and which therefore require control during brewery fermentations, are reviewed. Copyright © 2014 The Institute of Brewing & Distilling     

高浓酿造啤酒发酵周期的研究进展

高浓酿造是采用高浓麦汁发酵,之后进行稀释的啤酒酿造技术,该方法可显著提高生产效率,被广泛应用于啤酒生产中。虽然高浓酿造技术基本发展成熟,但仍存在发酵周期长以及后稀释造成风味不平衡的问题。由于高浓麦汁的特性,会导致发酵不彻底、发酵缓慢以至于延长发酵周期。该文分别从原料、发酵条件、菌株质量方面对高浓酿造啤酒发酵周期影响因素作了综合阐述,并对解决发酵周期长这一问题进行了讨论,提供可行思路。     

啤酒酿造中的微生物污染

由于啤酒酿造的环境奈件,如营养丰富的麦芽汁、发酵过程中酵母产生的生长因子以及较长的发酵时间等非常适宜于微生物的生长,所以在啤酒酿造中许多环节都存在微生物污染的可能性。啤酒酿造过程中的微生物污染不仅会影响产品的质量,严重时还会给啤酒生产厂家造成一定的经济损失。介绍了啤酒酿造过程中的污染微生物的种类、来源以及对啤酒质量的影响。通过了解啤酒酿造中微生物的污染情况,可以有助于我们生产高质量的啤酒产品.     

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     

The Use and Effects of Lactic Acid Bacteria in Malting and Brewing with Their Relationships to Antifungal Activity,Mycotoxins and Gushing: A Review

Several metabolic properties of lactic acid bacteria (LAB) serve special functions, which directly or indirectly have impact on processes such as improved quality and safety and flavour development in the malting and brewing industry. LAB are widely distributed in nature and in spontaneous fermentations, often they are found to be the dominating microflora resulting in both the inhibition of spoilage bacteria and organisms. This review describes the applications of LAB in malting and brewing. Mycotoxins are naturally occurring toxic secondary metabolites of fungi that may be present in cereals. Several of these mycotoxins have been associated with human and animal diseases and are known to survive the brewing process. LAB have been shown to restrict the growth of the most important toxigenic fungi thereby reducing the formation of these harmful toxins. The occurrence of mycotoxins in cereals is discussed and their effect in beer is reviewed. The main features of this review are: (I) LAB starter cultures in malting and brewing (II) production of acid malt; (III) biological acidification of mash and wort in brewing; (IV) bacteriocins produced by LAB in brewing; (V) LAB and anti‐fungal activity; (VI) mycotoxins in cereals.     

The Horace Brown Medal Lecture: Forty Years of Brewing Research

Horace Brown spent fifty years conducting brewing research in Burton‐on‐Trent, Dublin and London. His contributions were remarkable and his focus was to solve practical brewing problems by employing and developing fundamental scientific principles. He studied all aspects of the brewing process including raw materials, wort preparation, fermentation, yeast and beer stability. As a number of previous presenters of the Horace Brown Lecture have discussed Brown's achievements in detail, the focus of this paper is a review of the brewing research that has been conducted by the author and his colleagues during the past forty years. Similar to Horace Brown, fundamental research has been employed to solve brewing problems. Research studies that are discussed in this review paper include reasons for premature flocculation of ale strains resulting in wort underattenuation including mechanisms of co‐flocculation and pure strain flocculation, storage procedures for yeast cultures prior to propagation, studies on the genetic manipulation of brewer's yeast strains with an emphasis on the FLO1 gene, spheroplast fusion and the respiratory deficient (petite) mutation, the uptake and metabolism of wort sugars and amino acids, the influence of wort density on fermentation characteristics and beer flavour and stability, and finally, the contribution that high gravity brewing has on brewing capacity, fermentation efficiency and beer quality and stability.