麦汁混浊原因及主要解决措施

麦汁产生混浊的原因主要有原料（麦芽、大米、玉米、酒花）质量、原料粉碎度、糖化工艺、过滤条件（入醪刀速、阀门开度、耕糟刀高度）、煮沸条件（煮沸强度、麦汁pH、煮沸时间）、回旋沉淀效果等。解决麦汁混浊的主要措施：包括提高麦芽、辅料以及酒花的质量;控制麦芽和辅料的粉碎度;控制糖化工艺、麦汁过滤洗糟和麦汁煮沸条件及沉淀冷却效果。（孙悟）     

麦芽汁的提取与影响因素

<正> 在完成糖化处理的糖化醪中,含有溶解和不溶解的物质。其中的水溶液部分是麦芽汁,不溶性部分是废麦糟。废麦糟主要由麦壳、籽苗和其他在糖化过程中还没有溶解的物质组成。由于只有麦芽汁可用于生产啤酒,故必须将麦芽汁和废麦糟分离。这个分离过程,就是所谓的麦芽汁过滤,又可称为糖化醪分离。 为了达到高产率的生产,麦芽汁的过滤要求尽可能地回收抽提物,其过程可分为两个阶段: 1.初次麦芽汁的流出(主糖化醪) 2.废麦糟的淋洗(二次麦芽汁)     

啤酒糖化过滤槽改造带来的效益

糖化过程麦汁过滤质量 (麦汁澄清度、麦汁过滤速率、麦汁组份 )直接影响麦汁的组成和发酵。由于本公司原过滤槽设计不甚合理 ,出现麦汁回流时间长 ,麦汁中混有麦皮 ,过滤速度慢 ,谷皮成份溶出等现象。1　原过滤槽设计存在的问题1 1　过滤槽筛板空隙较大而且不平 ,可漏过麦皮和细渣 ,过滤槽表面分布力排布 ,造成糟层紧密 ,过滤阻力增大 ,过滤速度减慢 ;1 2　耕刀高度固定 ,不能调节 ,没有充分定位 ,容易破坏糟层 ,头道麦汁有破碎糟带入 ,使细渣和麦皮进入麦汁 ,麦汁虽清亮但仍有碎裂粉带入麦汁 ;1 3　过滤周期达 3小时 ,接触麦汁时间长 ,造成…     

提高糖化车间原料的利用率

比较不同糖化车间的设计，浸出物产量是主要的考虑因素之一，糖化车间浸出物利用率好坏，可以用糖化车间原料利用率（OBY）来衡量，浸出物的利用率高主要是过滤过程（也就是麦汁从酒糟中分离和后续的洗糟过程）效率高的结果。然而，过滤过程不是影响糖化车间原料利用率的唯一因素．糖化车间的其它过程也会影响浸出物的浸出、可过滤言和洗糟效果，因此，对糖化的每一步骤进行控制和优化，才能使浸出物达到最大本论文的结论表明进行浸湿细粉碎，各指标特性不会有所损失，但可以提高糖化车间浸出物的收得。对于过滤槽，改变其设计及麦汁管道收集区的管道教目，同时改进耕刀，可以提高浸出物的收得和充分的；中洗糟层，糖化车间的自动化、智能化的控制设备的应用，可以进一步的提高糖化车间原料利用率和提高过滤过程的控制。     

香糟卤气味模拟物微胶囊包埋条件的优化

为减少香糟卤在贮藏过程中的香气损失,本研究选用9种香糟卤关键香气化合物乙酸乙酯、乳酸乙酯、乙醇、丁二酸二乙酯、苯乙醇、异戊醇、醋酸、糠醛、2-羟基-4-甲基戊酸乙酯为芯材,以大豆分离蛋白、麦芽糊精为壁材,通过对大豆分离蛋白添加量、均质时间、乳化剂添加量和芯材添加量四个因素进行单因素和响应曲面实验对包埋条件进行优化,得到最佳条件为:大豆分离蛋白的添加量为4.11%,乳化剂添加量为2.22%,芯材添加量为19.33%,均质时间为7.39 min,得到微胶囊的包埋率为70.12%,验证值与模型预测值(69.59%)非常接近,证明了回归模型拟合较好。因此,响应曲面优化香糟卤模拟物的微胶囊包埋条件是可行的。     

酿酒酵母生产谷胱甘肽分批发酵动力学研究

以麦芽汁为发酵培养基,对7.5L 自动发酵罐中酿酒酵母Y518 分批发酵生产谷胱甘肽的实验数据进行分析,建立谷胱甘肽分批发酵动力学模型。通过对符合菌体生长的Logistic 方程、产物生成的Luedeking-Piret 方程和基质消耗的物料衡算方程进行最优参数估计和非线性拟合,分别得到了相应的动力学模型和最佳模型参数值。对动力学模型的拟合曲线进行分析,发现模型的计算值与实验值能较好地拟合,表明本实验建立的分批发酵动力学模型能较好地反映谷胱甘肽分批发酵过程。     

以糙米为主要原料的灵芝深层发酵培养基优化

以糙米、麦芽、黄豆芽为灵芝深层发酵培养基的原料.探索工业化生产全天然灵芝保健饮料的新途径.运用D-最优混料回归设计优化灵芝发酵培养基,结果表明:在三者体积比例限定范围内,糙米浆、麦芽汁和黄豆芽汁(可溶性固形物含量分别为12%、12%和2%)混料体积比为4:1:5时,灵芝菌丝干重达到最大值.说明D-最优混料回归设计方法适用于优化灵芝深层发酵培养基.     

复合黄精饮料的配方及工艺优化

以黄精、麦芽、陈皮、薄荷为原料,开发一种复合黄精饮料。以黄精多糖含量为指标,采用单因素试验和L₉(3⁴)正交试验对黄精的提取工艺进行优化;通过单因素分析,探讨黄精麦芽复合汁、木糖醇、陈皮汁和薄荷汁添加量对产品感官品质的影响,并以色泽、滋味、香气、组织形态为评价因素,结合利用L₉(3⁴)正交试验设计,以模糊数学感官评价法优化了复合黄精饮料黄精麦芽复合汁、木糖醇、陈皮汁和薄荷汁的配比。结果表明:黄精最佳提取工艺为:料液比1︰20(g/mL),提取时间2 h,提取次数2次;复合黄精饮料的最佳配方为:黄精麦芽复合汁添加量20%,木糖醇添加量6.5%,陈皮汁12%,薄荷汁10%。在此配方下制得的饮料具有独特的黄精风味,口感清凉,营养丰富。此次试验为复合黄精饮料研制提供理论基础和科学依据。     

人工神经网络在中浓纸浆流体化仿真研究中的应用

中浓纸浆悬浮液在剪切室内流动时,其所受剪切应力与湍流发生器的几何形状、转速及浆料浓度都有关系,通过改进算法的BP网络对实验数据的拟合,人工神经网络模拟仿真了各个因素对中浓纸浆所受剪切应力产生的影响,此外通过网络训练达到的稳定模型,可以预测中浓纸浆在更高浓度和湍流发生器转速下所受的剪切应力值.     

组盖机圆柱凸轮轮廓线的设计与分析

设计了组盖机圆柱凸轮机构的凸轮轮廓线,对其曲线进行了拟合,建立了SolidWorks三维模型,并对五次多项式曲线拟合的圆柱凸轮和正弦曲线拟合的圆柱凸轮在Adams中进行了动力学仿真,对仿真结果进行了对比分析,表明试验设计的凸轮轮郭线可用于实际组盖机样机的圆柱凸轮机构制造。     

Impact of full-scale brewing processes on lager beer nitrogen compounds

This paper analyses in a full-scale industrial process firstly the nitrogen compounds in all-malt and in maize-adjunct worts, then their fate during the main brewing steps and finally the influence on them of two different separation technologies: mash filter (Meura 2001) and lauter tun (Steinecker FVAS 26). Data showed that (1) maize-adjunct worts have a lower total nitrogen compounds than all-malt worts; (2) assimilable nitrogen represents 20–24% out of the total nitrogen in both all-malt and in adjunct worts; (3) free amino nitrogen nearly doubles in all-malt compared with adjunct worts; (4) proline and asparagine are the most abundant amino acids in both worts; (5) ammonium disappears during fermentation in wort with the lowest nitrogen content, i.e. in maize-adjunct wort. Moreover, the total nitrogen is reduced in all-malt by 80% with the Steinecker FVAS 26 lauter tun and 25% with the Meura 2001 filter, while in adjunct worts by 87% with the Steinecker FVAS 26 lauter tun and 29% with the Meura 2001 filter. After mash filtration, the content of assimilable nitrogen remains to be adequate for an efficient fermentation, but after lauter tun separation, the assimilable nitrogen reaches values that may compromise the regular fermentation process in both all-malt and adjunct worts. Therefore, when using lauter tun, we have to intervene to reduce its impact on nitrogen compounds and/or plan the wort nitrogen supplementation to overcome the stuck and sluggish fermentations.     

Influence of Lauter Turbidity on Wort Composition,Fermentation Performance and Beer Quality — A Review

This review paper covers a variety of aspects concerning lauter turbidity and wort clarity that have been published in the past decades. The components of wort which are connected to an increased lauter turbidity, such as lipids and long‐chain fatty acids, are presented as well as how the further steps of wort production, i.e. wort boiling and clarification, have an impact thereon. Besides the influence of lauter turbidity on wort quality, technical aspects affecting lauter turbidity are discussed by comparing different lauter systems such as lauter tun, mash filter and strainmaster. It is further highlighted, how lauter turbidity and its components influence fermentation performance and yeast vitality. Finally, the consequences of increased wort turbidity for the resulting beers in terms of flavour quality, flavour stability, non‐biological stability and foam stability are described.     

Study on the Membrane Filtration of Mash with Particular Respect to the Quality of Wort and Beer

The quality of a membrane filtered wort, and the beer from it, is different from that produced with a lauter tun or mash filter. A membrane is capable of producing a clear wort in terms of turbidity while solid contents, in particular larger molecular substances, are retained. The selectivity of separation is not directly set by the membrane's pore size but rather by the formation of the fouling layer. Thus an interaction between technical filtration parameters and selectivity determines the quality of the resulting wort and beer. The filterability of a beer produced with a membrane filter system for lautering was considerably better when a poorly modified malt was used and foam stability was worse when a normally modified malt was used. For all other properties examined in the beers, no significant differences between lauter tun and membrane filtration including sensory characteristics were observed.     

探讨革新的糖化生产技术与设备

<正> 当今先进的技术已将啤酒酿造工艺带进了另一个新国度。今天,高质量的麦芽糖化工艺和低麦汁浊度已成为啤酒质量和味道稳定性的重要指标。 以融汇新技术知识为基础,针对于设备的功能性和有效利用性,ZIEMANN公司不断在改进其糖化设备     

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.     

提高糖化生产能力的新工艺

采用湿法粉碎、新型高效过滤槽、两个煮沸锅等新的工艺流程和技术，不改变原料配方和原料等级，只增加少量投资，可提高糖化生产能力和麦汁质量。     

The effects of three mash separation systems on the isomerisation of hop alpha-acids

This study investigates the effects of wort composition from three lautering systems on hop utilisation at different hop boiling and dosing times. A response surface methodology was applied with 60 single tests at a 5 litre scale. The parameters, which were varied, were lautering system, boiling time without hops, boiling time with hops and α-acid dosage. It was shown that the wort composition from the different lautering systems requires different boiling times or enables the reduction in boiling time with hops. Although the pH and original gravity of the lauter tun and mash filter worts were similar, different boiling times were necessary to achieve the same concentration of iso-α-acids. Further, there were variations in fatty acid composition of the worts. In order to be able to assess the effects on a larger scale, six brews were performed in a 10 hL pilot brewery. The utilisation of hop bitter substances differed despite the same boiling time and the same α-acid dosage in relation to the total quantity of wort. In addition, no significant losses of hop bitter substances were observed in the wort from a continuous mash filtration system due to the process related higher dosage of α-acid. Both sets of experiments showed that the boiling times depend on the wort composition and increased as follows: novel continuous mash filtration system < mash filter < lauter tun. The results lay the foundation for calculating the optimal parameter settings for each brewery to optimise the hop isomerisation rate. © 2020 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling     

THE FATE OF AMINO ACIDS DURING MASHING AND HOP BOILING

In an infusion mash system the concentration of all α amino acids in sweet wort reaches a maximum value when approximately one-third of the total volume extracted has been run from the mashing vessel. The relative concentrations of each α amino acid in wort vary throughout the mash tun extraction owing to differences in rate of extraction of the amino acids and to the quantities produced by peptidase activity in the mash tun. The relative proportions of proline, alanine, glutamine and asparagine in the total α amino nitrogen content of wort decrease appreciably as the mashing process proceeds. Copper boiling results in the partial destruction of methionine, glutamic acid, lysine, arginine and valine present in sweet wort together with an increase in the concentration of ammonium ion in the wort.     

THE MOLECULAR STRUCTURE OF GELPROTEIN FROM BARLEY,ITS BEHAVIOUR IN WORT-FILTRATION AND ANALYSIS

Gelproteins from barley and malt play a major role in the lauter tun filtration. These proteins (called glutenin in wheat) are partly broken down during malting and then aggregate during mashing. These aggregates form a part of the upper layer of the spent grains (the ‘oberteig’). To obtain more insight into this mechanism the composition of gelproteins of different cultivars of barley were analysed using various electrophoretic techniques. From this work a model can be proposed in which the protein, like its counterpart in wheat consists of high molecular weight (HMW) subunits as a backbone and low molecular weight (LMW) subunits as side chains, joined by inter-and intra-molecular disulphide bonds. During malting the disulphide bonds are reduced and subunits are broken down by proteolysis. During mashing a complex is formed between residual gelprotein in the malt and the glutelins, which gives rise to an impenetrable layer on the spent grains. The quantity of gelprotein as analysed by high pressure liquid chromatography (HPLC) or densitometry of Sodium dodecyl sulphate polyacrylamide electrophoresis (SDS—PAGE) patterns of HMW subunits showed a negative relationship to the lauter tun filtration rate.