小麦啤酒的研制

以小麦芽为主要原料，采用加酶糖化法，加麦汁澄清剂煮沸，浮选法去除冷凝固物，滤酒时添加ＰＶＰＰ、“快８３”硅胶和复合抗氧剂，用二氧化碳背压、二次抽真空法包装等先进可行的技术，酿制出风味独特，非生物稳定性好的小麦啤酒，有效解决了小麦啤酒生产中麦汁过滤困难和保质期短的难题。     

具有国际水平的“旋流沉淀槽”试制成功

自动除糟、浸出物回收和防氧化的旋流沉淀槽系统以前,慕尼黑工业大学啤酒学院的名教授 L·Narziβ曾说过:麦芽质量好时,可以不用浮选法,麦芽质量不好时,应该采用去冷凝固物的措施——浮选法(见《食品与发酵工业》,1986,第3卷,85页)。最近 K·Unter Stein 总结大容器发酵罐的经验后,提出对麦汁质量(物理方面)的要求如下:(1)过滤出的麦汁应尽可能清亮透明,不含固体物(对麦汁过滤的要求);(2)冷麦汁必须不含热凝固物(对旋流沉淀槽的要求);     

麦汁澄清度对啤酒质量的影响

1.麦汁澄清与凝固物的析出在啤酒酿造中,煮沸后的麦汁在进入发酵罐前,需进行一系列处理,如麦汁冷却,通氧,冷、热凝固物的析出、分离等。最终定型麦汁的质量,除了要求麦汁组分合理外,对于冷、热凝固物应尽可能的分离,使处理后的麦汁清亮、透明。决定麦汁澄清的关键在于凝固物的分离程度。提高麦汁澄清度,可有效     

热麦汁罐过滤系统

目前从热麦汁中分离凝固物和废酒花的工艺和设备有很多种。但是这些方法都给糖化工人操作带来一定的困难。第一种方法是分取法,即在盛热麦汁的罐内进行沉淀分离,将滤出热麦汁中的废酒花、凝固物沉淀到热麦汁罐底。虽然采用这种方法成本非常低,但是它大大增加了工人的劳动强度;此外,在分离凝固物和废酒花的过程中,会出现严重的污染。从饱和残渣中分离出残余麦汁也比较困难,而且还会损失大量的麦汁。     

关于几种麦汁澄清剂的对比试验

麦汁澄清度是生产优质啤酒的基础.通过对卡拉胶、复合硅胶和单宁对啤酒麦汁澄清对比试验.在煮沸结束前10分钟加入,蒸发强度控制在9%,3.0×10-4(300ppm)颗粒卡拉胶能加快冷浊蛋白质沉淀,使麦汁清澈透明;1.5×10-4(150ppm)的复合硅胶能有效吸附单宁、多酚、蛋白质,可明显去除热凝固物;单宁酸对除去热凝固性氮物效果明显,但与蛋白质结合后易使麦汁混浊.(永光)     

从热凝固物中回收麦汁方法的一点改进

我厂经过反复试验,找到了一个较为简便可行的从热凝固物中回收麦汁方法:热麦汁经旋涡沉淀45分钟后进行薄板冷却,槽底的沉渣(热凝固物)用少量80℃左右的热水冲入一次糖化过滤槽内(于第一次洗糟时放入)。热凝固物在沉淀槽停留时间,不宜超过8小时。我们体会,此种回收麦汁的方法有如下几点好处:(1)增加糖化收得率。经     

啤酒讲座(八) 第五讲 麦汁的处理

麦汁的处理包括麦汁过滤、麦汁煮沸、添加酒花、麦汁热凝固物的处理、麦汁冷却、麦汁冷凝固物的处理以及麦汁处理过程中的副产物等。一麦汁过滤1.麦汁过滤的目的糖化工程结束后,应该及时把糖化已经溶出的糖液和没有溶解的麦皮、蛋白质凝固物和原料中的杂质分离出来。被分离出来的糖液称为麦汁,加水洗涤出来的糖液称为洗涤麦汁,遗留在过滤设备中的杂质称为麦糟。麦汁和麦糟的分离时间要求越短越有利于麦汁的质量,麦糟浸泡时间长了,麦皮中的色素被浸出,会给麦汁带来不良的苦涩味和麦皮味。把麦汁和麦糟分开的方法称为麦汁过滤。     

秦皇岛工厂回旋沉淀槽的改造

回旋沉淀槽的作用主要是分离麦汁中的热凝固物和酒花糟等.麦汁从煮沸锅进入回旋沉淀槽后,如回旋沉淀效果不好,热凝固物很难被分离出来,麦汁的浊度高,影响酵母发酵,进而影响啤酒质量.     

回旋沉淀槽停留时间与麦汁TBA、色度、浊度的关系

回旋沉淀槽的作用主要是分离麦汁中的热凝固物和酒花糟等。如果回旋沉淀槽分离效果好且停留时间充足的话,热凝固物和酒花糟能很好地分离出来。但是不能为了分离热凝固物而让麦汁在回旋沉淀槽里停留的时间太长,这样会影响麦汁的质量。一般情况下,回旋沉淀槽等硬件设备是相对固定的,抛开其它方面因素的影响,我们通过对比实验来研究回旋沉淀槽停留时间与麦汁 TBA、色度、浊度的关系。     

麦汁冷却薄板前安装过滤器改善麦汁澄清度

浑浊麦汁中含有大量的脂类和长链脂肪酸,影响啤酒风味稳定性,还可能导致酵母细胞粘连凝固物,影响酵母的正常发酵。同时浑浊麦汁中的酒花、麦皮、热凝固物等随麦汁进入冷却薄板,易使薄板堵塞,影响麦汁的冷却速度。为此,我们在麦汁冷却薄板入口处增加一个过滤器以提高麦汁的澄清度。1改造过程将冷却薄板麦汁入口处管路截断,安装带有过滤器的管路,过滤器内滤网可以拆卸、更换,方便清理过滤出来的杂质。2改造效果跟踪1)安装过滤器前跟踪麦汁冷却时间、冷却     

PREDICTION OF WORT COLD BREAK PERFORMANCE OF MALT AND ITS APPLICATIONS

A new test for wort cold break performance of malt was developed, based on laboratory mashing and boiling, followed by adding a range of concentrations of copper finings at different wort pH values. The test predicted successfully brewery wort cold break performance, with malts being ranked on the basis of production of wort cold break which required a low concentration of copper finings for precipitation and flocculation. A relationship between wort pH and the concentration of copper finings required to give an acceptable cold break was established with both brewery and laboratory worts. A strong correlation (r = 0.922, p << 0.01) was found between copper finings concentration and the two variables wort pH and the amount of cold break protein. Differences in brewery cold break performance were explained largely by a difference in wort pH, although other as yet unidentified factors appeared to be involved. Cold break performance of malts was affected by both crop year and protein modification, but not total nitrogen or total soluble nitrogen. A brewing trial is described in which wort pH is increased at the end of boiling, leading to significant improvements in both cold break and isinglass finings performance.     

The Loss of Hydrophobic Polypeptides during Fermentation and Conditioning of High Gravity and Low Gravity Brewed Beer

The object of this study was to investigate the loss of hydrophobic polypeptides, which are important for foam quality and stability in finished beer. Loss of hydrophobic polypeptide due to fermenter foaming occurs during transfer of fermented wort since a gradient of hydrophobic polypeptides towards the surface is created during fermentation. Due to higher polyphenol levels in high gravity (20°Plato) wort, more hydrophobic polypeptides are lost due to cold break (cold trub) precipitation compared to low gravity (12°Plato) wort. Another important factor affecting the loss of hydrophobic polypeptides could be proteinase A activity during fermentation, especially in high gravity fermentation where the yeast is exposed the higher stress. During high gravity fermentation, where osmotic pressures are higher, ethanol levels become greater, and nitrogen‐carbohydrate ratios are lower, more proteinase A is released by the yeast. This release of proteinase A into fermenting wort could have implications for the foam stability of the finished product.     

THE FATE OF HUMULONE DURING WORT BOILING AND COOLING

Variations in the nature of the grist, mashing temperature, gravity and content of anthocyanogens of wort influenced the yield of break obtained after boiling with humulone, but not the bitterness of the resulting worts. Only small amounts of resin were found on the break and although increased break formation resulted in increased adsorption of resin this did not lead to measurable differences in the bitterness of wort. The bitterness of the cooled wort was independent of the degree of aeration and speed of cooling.     

啤酒酿造过程中萜烯醇类化合物变化规律

采用基于顶空固相微萃取-气相色谱质谱技术(HS-SPME/GC-MS)建立的啤酒中酒花物质的检测方法,跟踪了啤酒酿造过程中源自酒花的5种萜烯醇类香气化合物的变化规律,初步为啤酒厂酒花配方及工艺调整奠定了理论基础。通过对糖化过程中不同酒花配方、不同煮沸方式及酒花添加工艺对冷麦汁中萜烯醇类化合物含量影响的研究,发现冷麦汁中的萜烯醇类化合物主要受最后一次添加酒花的添加量和添加时机影响,最后一次酒花在煮终回旋前添加较煮终前10 min添加,更利于萜烯醇类化合物在冷麦汁中的保留,这与国外的late-hopping工艺相一致;与煮终前10 min最后一次添加相比,在煮终回旋前最后一次添加酒花能使冷麦汁中里那醇含量提高209.4%,α-萜品醇为91.2%,香叶醇为31.4%,橙花醇175.0%。通过研究发酵过程中萜烯醇类化合物的变化规律,发现5种萜烯在发酵过程中呈上升趋势,且它们之间可能被酵母相互转化。     

The Role of Small Wort Peptides in Brewing Fermentations

The utilisation of small peptides by brewing yeast is poorly understood despite a wealth of information on peptide transport by other microorganisms. A novel method for detection, isolation and measurement of small peptides during brewery wort fermentations was used to monitor utilisation by ale and lager yeast strains. Oligopeptide levels in wort were found to fluctuate throughout the fermentations. Measurement of extracellular protease activity provided evidence that yeast are able to continually regulate protease production in order to break down wort polypeptides into utilisable nitrogeneous materials.     

Flavor, Viscosity, and Color Analyses of Hot and Cold Break Tomato Juices

ABSTRACT: Two methods are used commercially to produce tomato juice: hot break and cold break. Tomatoes were chopped and allowed to sit for various time intervals to simulate the cold break process. Zero was hot break, and 2 to 24 min represented cold break. Sensory, volatile, color, and viscosity analyses were conducted to determine which hold time produced the optimum juice. Sensory panelists rated 15 min cold break most fresh and liked over hot break. Lipoxygenase-initiated volatiles increased from hot to cold break. No overall color difference was found between hold times. Viscosity decreased from hot to cold break. The cold break process can be used to produce a premium flavored tomato juice.     

Fungal Hydrophobins in the Barley‐to‐Beer Chain

Fungal hydrophobins have been shown to induce gushing of beer. In order to study the occurrence and fate of hydrophobins at different stages of the production chain of beer, barley samples artificially infected in the field with Fusarium culmorum, F. graminearum and F. poae were collected during the growing period as well as during various stages of the malting process. In addition, naturally infected malt was brewed in pilot scale and samples were collected throughout the process. The samples were assayed for hydrophobin content using an ELISA method. The results showed that fungi produced hydrophobins that accumulated during barley grain development in the field, but that production was more pronounced during malting. Prolonged storage of barley tended to reduce the ability of fungi to produce hydrophobins in malting. Studies on the fate of hydrophobins during the brewing process revealed that mashing released hydrophobins from the malt into the wort. Some loss of hydrophobins occurred throughout the brewing process with spent grains, cold break (wort boiling) and surplus yeast. In addition, the beer filtration step reduced hydrophobin levels. Despite the substantial loss of hydrophobins during brewing, the level was high enough to induce the gushing detected in the final beer.     

LIPIDS IN WORT

Material balances have been constructed for lipids during wort preparation in commercial breweries. 4–5% of malt lipids were released into the wort using the mash filter, 1·0% with the lauter tun but only 0–3% with the mash tun. Up to 30% of malt lipids may be oxidised during mashing. Hop products make a contribution to the lipids in the copper though these lipids are not readily extracted. Efficient removal of spent hops and hot break will ensure a low level of wort lipids in the fermentation vessel.     

THE USE OF FORMALDEHYDE IN RESTEEPING

Small-scale malting trials showed that resteeping in a solution of formaldehyde was more uniformly effective than resteeping in water in reducing rootlet yield and the overall malting loss. The hot water extract, the fermentability of the wort, and the formol nitrogen were the same in worts from malts prepared by resteeping in water or formaldehyde solutions. However, cold water extract was reduced, as was the total soluble nitrogen, by the presence of formaldehyde. The anthocyanogen level in the wort was reduced by about 73% when formaldehyde was used in the resteep liquor. The residue of formaldehyde in the unboiled wort was about I p.p.m. It is considered that, in view of the improved resteeping performance and the expected increase in beer stability resulting from the reduction in anthocyanogens and wort nitrogen, the use of formaldehyde in resteeping is worth evaluating on a larger scale. In addition the use of formaldehyde in the resteep liquor prevented fouling by micro-organisms and resulted in a cleaner malt.     

超氧化物歧化酶改善啤酒风味稳定性的研究

超氧化物歧化酶（SOD）能够清除活性氧自由基,减少活性氧自由基氧化作用引起的危害。在啤酒酿造过程中,原料中的SOD是否对酿造过程、成品啤酒的风味稳定性产生影响以及产生什么样的影响,相关的研究较少。本文研究了制麦、糖化以及发酵过程中SOD活性的变化及其对酿造过程的影响。结果表明：麦芽SOD活性和协定麦汁的还原力之间存在显著的正相关性。向麦汁中单独添加SOD或过氧化氢酶（CAT）时,可以抑制羰基化合物的形成;SOD和CAT的协同作用可以有效提高麦汁的内源性抗氧化力。发酵前单独添加SOD、同时添加SOD与CAT后的啤酒中,反-2-壬烯醛含量比对照分别降低了12．2％和14．4％,不同程度地提高了啤酒的风味稳定性。