Improving the Effectiveness of Isinglass Finings for Beer Clarification by Optimisation of the Mixing Process. Part 2: Pilot Scale Experiments

Previous work in the laboratory identified the benefit of a two stage mixing process after addition of isinglass finings to beer. Static (motionless) mixers have been selected as the mixer of choice for commercial applications. A pilot plant has been employed to identify the ideal quantity and format of mixing elements for each of the two stages. Experiments in three breweries have enabled the optimum mixers to be identified for the pilot rig. Mix quality produced by the static mixers has been measured using a technique called laser induced fluorescence. This information complements the finings performance data. For the pilot plant the optimum first stage mixer had ten mixing elements, and the optimum second stage mixer had a residence time of 1.1 s in the elements at a shear rate of 80–90 s^?1.     

Premixing of Isinglass and Silica Gel to Obtain Improved Beer Stability

Isinglass and silica gel have both been used successfully for clarification and stabilization of beer for many years. Most applications involve separate additions, but premixing is a possibility. This study investigated the effects of premixed treatments on filtration and stability. Kettle finings are also used extensively to remove proteinaceous material during wort boiling. This study was extended to observe the effects of finings on fermentation rate, filtration and stability. Isinglass and silica hydrogel treatment gave the most rapid filtration rate, but using them in combination gave no apparent benefit. The addition of kettle finings resulted in a more vigorous fermentation, although they did not appear to improve beer stability. Following storage at 4°C for 12 months, the most stable beer resulted from treatment with a combination of isinglass and silica xerogel, indicating that this form of treatment is a desirable method of beer stabilization.     

鱼胶澄清剂在啤酒工业中的应用

<正> 鱼胶作为啤酒澄清剂的应用已有上千年的历史,然而国内啤酒工业对鱼胶应用的认识尚浅。本文结合实例介绍鱼胶澄清剂的应用,以及其所带来的经济效益和优良品质。     

THE DETECTION OF ISINGLASS FININGS IN BEER

A method for the detection of isinglass finings in beer is described. Protein is precipitated from the beer with a large excess of sodium alginate and hydrolysed; the hydrolysate is examined colorimetrically for the presence of hydroxyproline. The presence of this imino acid, which is found in substantial proportions only in collagen and gelatin, indicates that the beer has been fined.     

THE EFFECT OF COLD BREAK ON THE FINING OF BEER

After fermentation the suspended particles in unfined beer can be classified into two groups: a) yeast and b) proteinaceous material associated with carbohydrates and polyphenols. These can be differentiated in terms of particle size using a Coulter Counter. Clarification by fining applied either in cask or as a pre-filtration technique is greatly affected by large concentrations of particles other than yeast. The majority of this mainly proteinaceous material has been shown to be derived from ‘cold break’ which remains suspended in the beer after fermentation. The amount of this material can be reduced significantly by the effective use of copper finings. In consequence, reduced levels of both auxiliary and isinglass finings have been shown to give more rapid overall clarification whilst producing a smaller volume of sediment.     

ESTIMATION OF ALGINATE,CARRAGEENAN AND FURCELLARAN IN BEER

Quantitative and semi-quantitative methods are given for estimating alginate, carrageenan and furcellaran at low concentrations in beer. A number of commercial beers and experimental beers known to have been brewed with either copper finings or auxiliary finings containing these acidic polysaccharides as active ingredients were analysed for alginate, carrageenan and furcellaran residues. The results show that alginate and carrageenan do not occur in finished beers at levels greater than 1 mg/litre. Using a serological technique which is more sensitive for furcellaran, it was found that levels of furcellaran in most finished beers were below 0.5 mg/litre, though a few beers contained this polysaccharide at about 0.5 mg/litre.     

CHARACTERISATION OF BEER PARTICLE CHARGES AND THE ROLE OF PARTICLE CHARGE IN BEER PROCESSING

Streaming current measurement has been shown to be an effective tool in measuring the net charge of beer particles. Using this method, it was demonstrated that non-microbiological particles of a number of beers could be either positively or negatively charged. Copper fining has been shown to significantly affect the net charge of the NMP in the resultant beer. Increasing the copper fining rate enhances the negative net charge of the NMP to a limiting value at which the addition of further copper finings has no effect. This is believed to correspond to the complete removal of all of the positively charged NMP by copper fining. The reduction in pH during fermentation results in the production of further positively charged NMP. The presence of positively charged NMP has been shown to have an adverse effect on isinglass fining performance. These results suggest that choice of raw materials and process conditions play as much of a role in defining fining performance as does careful consideration of fining rates .     

Hop proanthocyanidins for the fining of beer

Fining agents are used in the clarification of beers; they help to reduce the time required to sediment suspended yeast cells and ensure the clarity and colloidal stability of beer. Following an adventitious observation during dry‐hopping experiments, we identified a fining activity associated with Saaz hops. Extracts of hop cones were subsequently shown to have the capacity to flocculate yeast and result in their sedimentation. This activity has since been identified in extracts of many different hop varieties and, significantly in spent hops, the co‐product resulting from commercial extraction of hops with either CO₂ or ethanol. Here we illustrate the activity of the novel finings extracted from spent hops following CO₂ extraction of Galena hops. The sediments formed on fining were compact, relative to those obtained when commercial isinglass was used to fine the same beers. The hop extracts were also effective in reducing 90° haze in beers under conditions designed to mimic both cask ale (12 °C) and lager (4 °C) type applications. The compounds responsible for the fining activity appear to be large (30–100 kDa, or more) polyphenols. Analysis of the polyphenols using colourimetric tests indicated the presence of proanthocyanidins. On acidic hydrolysis these generated cyanidin, which would be derived from a polymer composed of catechin and epicatechin subunits. The presence of these materials in spent hops offers the possibility to develop commercial products, with desirable fining properties, from an existing co‐product stream. Furthermore, the finings are derived from a traditional ingredient of the brewing process. Copyright © 2015 The Institute of Brewing & Distilling     

调配型黑啤酒的研制

以淡色啤酒为基酒,使用黑啤酒浓缩液、焦香浓缩液和焦糖色等物料,通过色度测试、口味测试和小型试酿,得出最优的配方。使用浓缩液方法生产黑啤酒,选择在过滤阶段完成,可达到精简工艺,便于设备清洗和酵母管理等效果,且生产成本较传统酿造法低,该法可行性高、经济效益明显,符合低碳、环保生产发展。     

LOW PROANTHOCYANIDIN MALTS FOR PRODUCTION OF CHILLED AND FILTERED OR FINED BEER

Malts which conform to most commercial specifications can be prepared from Galant barley, which is low in anthocyanogens. However, the malting performance of this variety is only medium and considerable care is required during kilning in order to avoid excessive colour development. Beers brewed from Galant malt have greatly improved chill haze stability, although flavour stability is not significantly affected. Fining and filtration studies on rough beer and forcing tests for the development of non-biological haze in finished beer indicate that the use of Galant malt greatly reduces the extent of precipitation of particulate matter during brewing, conditioning and subsequent storage. This can result in considerable savings in the use of finings, and in longer filter runs since levels of addition of body feed can be reduced. It is suggested that the use of low anthocyanogen malts could, with some beers, reduce the necessity for chilling prior to and during filtration.     

Rotary jet head – a device for accelerating the fermentation process in brewing

The world beer market is dominated by lagers, with production estimated at hundreds of millions of hectolitres per year. The vast majority of the beer is produced using CCT (cylindro‐conical tank) technology. Fermentation and maturation are time‐consuming processes and the bottlenecks of beer production. A rotary jet head (RJH) – a device originally used as a cleaning device – is proposed for use as a tool to provide homogeneity in the tank and to increase the activity of the yeast cells by keeping them in suspension during the fermentation process. The main objective of the study was to analyse the impact of mixing the content of the fermentation tank (by the means of an RJH) on the time of fermentation, maturation and cooling. The experiments were carried out under full industrial operational conditions. It was concluded that mechanical mixing, in a CCT of 3800 hL, shortened the time of lager beer production process by ca. 15%, the time of fermentation by ca. 24 h and the cooling time by ca. 35 h. Copyright © 2016 The Institute of Brewing & Distilling     

COLLAGEN CHEMISTRY IN RELATION TO ISINGLASS AND ISINGLASS FININGS. PART II

The intrinsic viscosities of collagen finings were higher in the absence of citrate buffer than in its presence. The lower values, which vary among different preparations, well reflect their relative fining abilities. The latter are due to molecules which are, in most cases, larger than monomers, and the differences in intrinsic viscosity are ascribed to differences in molecular structure in the original tissues. The higher values observed in the absence of citrate are due to the aggregation of these molecules; however, these dissociate in beer and so do not assist fining in this form. The effect of the rate of flow in the viscosity measurements is considered. Differences in the shrinkage temperature of isinglass are related to differences in macrostructure, but these are not necessarily related to the stability of the protein in solution. The denaturation temperatures (T_D° C) of all the finings examined were in the range 29·2–30·3° C.     

山药啤酒的研制

以山药、麦芽为原料,酶法糖化制汁,接种啤酒酵母发酵研制了山药啤酒。将新鲜山药制备成山药粉,与麦芽在复合酶的作用下糖化制汁。采用正交试验设计研究复合酶的添加量、添加阶段、作用时间、山药粉添加量对山药、麦芽mix中还原糖量、α-氨基氮含量的影响。结果表明,酶法制备山药、麦芽混合汁的最佳工艺条件为酶的添加量0.36%,添加阶段45℃,作用时间17min,山药粉添加量35%。于此工艺下制备的山药、麦芽混合汁经酵母菌代谢后,高级醇含量为55.8mg/L,双乙酰0.06mg/L,酒精度3.91%(W/W),真正发酵度66.4%。酿制的啤酒不仅具有大麦芽啤酒的风味,并且还富含了山药中多种氨基酸和抗癌物质,不失为一种较好的功能性饮品。     

AN INVESTIGATION OF FININGS FROM FISHSKINS

Finings have been produced from the skins of a variety of cold and deep water fish and the properties of these solutions compared with those of conventional isinglass finings. Although appreciable fining action was obtained with certain of the fishskin finings—notably those from ling—the variable quality and general inferiority to isinglass precludes the use of these materials as an alternative source of collagen in finings production.     

THE MOLECULAR WEIGHT AND SOLUBLE COLLAGEN CONTENT OF FININGS IN RELATION TO ITS FINING POTENTIAL

The fining efficiency of different samples of isinglass finings is related to the molecular weight of the finings molecules in true solution, those of highest molecular weight being the most efficient. The molecular weight is studied by means of intrinsic viscosity. Contributions from soluble aggregates are avoided by carrying out the measurements in citrate buffer. Soluble aggregates occur in finings but do not contribute to fining. The significance of intrinsic viscosity and soluble collagen content in the preparation of finings is examined.     

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.     

COLLAGEN CHEMISTRY IN RELATION TO ISINGLASS AND ISINGLASS FININGS—A REVIEW

The significance of present knowledge of the structure of the protein collagen to the study of isinglass and the finings derived from it is examined. It is suggested that differences in fining efficiency of solutions prepared by identical processes from different sources of isinglass are due to variations in the size of the molecules in the finings.     

在靠近流浆箱处淀粉和填料同时混合工艺

采用闪急混合工艺使得在最接近流浆箱处向浆料中加入助留剂和施胶化学品等造纸添加剂,并使之迅速和有效地混合。这项多功能混合技术可以做到在同一地点同时将填料、助留剂一起加入到流浆箱中。该工艺操作简单,具有非常短的响应时间,填料留着率更高,纸张性能更优越。由于减少了添加剂在过程中的循环,响应时间非常快速,减少了传统混合过程的水或滤液的量,从而降低了能源消耗,降低了添加剂用量并使工艺过程净化。     

利用先进的“创捷”闪急混合系统在接近流浆箱处同时添加填料与助留剂

“创捷”闪急混合工艺使造纸助剂如助留剂和施胶剂迅速且高效地在最接近流浆箱的部位注入成为可能。这种新技术也使得在接近流浆箱处加入填料成为可能,并可同时同部位加入助留剂。该工艺简单、响应快,可改善填料留着率及纸张性能。     

使用单宁提高烹调黄酒非生物稳定性的研究

单宁是一种植物多酚,它可以与溶液中的蛋白相结合形成沉淀,提高溶液的非生物稳定性。用单宁作为黄酒的澄清剂具有添加量小,使用方便,作用时间短,效果明显等优势。把单宁作为提高黄酒非生物稳定性的添加剂具有重要的推广价值。