Clarification of beer

Noordman TR, van der Noordt M, Hardenbol AFC, Peet Cl, Broens L, and Mepschen A. Practical experiences with membrane filtration for the clarification of beer on an industrial scale. Presentation 0-15 of World Brewing Congress 2004, San Diego, CA, 2004. 

Because of its ability to form complexes with many chemical substances (see Section 3.2.5) and its large surface area in the swollen state, normal crospovidone is a good filtration auxiliary. It is particularly useful for selectively binding polyphenols, e.g. tannins in the form of an insoluble complex. As in the clarification of beer and wine, this feature can be used in the preparation of galenical products, particularly tinctures, aqueous and alcoholic extracts and medical wines, to extend their long-term stability by preventing precipitation. 

In the clarification of beer by cross-flow microfiltration the paper by Trag rdh and Wahlgren [58] seems to be one of the sporadic examples of this application. Here the use of 0.5 xm membranes (Membralox) is necessary to maintain the taste of the beer 0.2 pm shows an unacceptable retention of proteins and colour. Bacteria were retained by the 0.5 pm membrane. 

Yet another use for casein is for stabilisation, colour removal and clarification of beer and white wine [85,86]. Casein is listed as a component of various dietary and infant foods [87,88]. 

Raisins are used in the tanning industry, in the clarification of beer and in the manufacture of chewing gum. Food trees provide wood, which can be used for making furniture, etc. 

To conclude this section, it must be emphasized that the conversions described above are to be avoided whenever possible (because of inherent errors in such procedures), by using a method which gives the desired type of distribution directly. Different methods give different particle size distributions (see Table 2.7, section 2.7) and the selection of a method is made on the basis of both the particle size and the type of distribution required. In most applications in solid-fluid separation, it is the particle size distribution by mass that is of interest because, usually, we are interested in gravimetric efficiencies and mass balances. There are, however, cases such as liquid clarification where the turbidity of the overflow is of importance (clarification of beer etc.) and particle size distribution by surface or even by number is more relevant. 

Available speeds range between 4500 and 8500 rev. min , flow rates from 2.5 to lOm h and bowl diameters from 335 to 615 mm. Multi-chamber centrifuges, apart from the separation of grinding swarf from cutting oils already mentioned, are mainly used for the clarification of beer, wine, fruit juice and varnishes. 

Separation of biological materials (cells) is another area of fast development and this is at its strongest in clarification of beer (removal or recovery of yeast). 

Centrifugation Wastewater and sludge thickening metalworking coolants cleaning purification of marine fuels dehydration of tar and clarification of beer, wine, fruit juice, and varnishes. 

In breweries, for example, hermetic centrifuges can be used for pre-clarification of beer ready for packing, with no carbon dioxide losses and no destruction of protein for the clarification of the cold wort, with a good clarification efficiency because protein particles are not destroyed. In dairies, hermetic centrifuges are used because milk is sensitive to both oxidation and shear. 

Uses.—The more common kinds of isinglass, especially the coarse Brazilian, are used by brewers for fining beer, and have been noticed in their application for that purpose. They are also employed for the clarification of wines, and various other liquids. 

Salicylic Acid.—100 c.c. of the beer, acidified with 5 c.c. of dilute sulphuric acid, are shaken in a separating funnel twice with 50 c.c. of a mixture of ether and petroleum ether in equal volumes, a few drops of alcohol being added to facilitate the clarification of the solvent. The ethereal liquids are filtered into a flask and the solvent distilled off on a water-bath, the small amount of hot residue bdng treated with 4 or 5 c.c. of water and, with shaking, a few drops of dilute ferric chloride solution. The liquid is filtered through a moist filter and if the filtrate is violet, the presence of salicylic acid is indicated. 

Representative applications Sterile filtration Clarification/sterilization of beer and Representative applications Continuous culture/cell recycle Filtration of oilfield produced water... 

Food beverage treatment—clarification of liquids (fruit juices, beer),... 

Inorganic membranes have also been used in the clarification of other fermented alcoholic beverages such as beer and vinegar in recent years. Two important applications of membrane filtration for beer production are the removal of bacterias and beer recovery from the so-called tank bottoms. They are treated in the following. 

Clarifying agents or flocculants are used to eliminate turbidity or suspend particles from liquids, e.g., chill haze in beer, precipitates in fruit juices and wines, and haze in oils. Often, they provide a nucleation site for suspended fines. Examples of clarifying agents are lime in sugar juice clarification, pectic enzymes to break down pectins in fruit juices, and gelatin for clarification of fruit juices. 

Publications on clarification of alcoholic drinks like wine and beer deal mainly with the treatment of wine. Advantages of ceramic membranes over classical methods are the reduction of operating costs (reduction of filter aids, less loss of product) and a better clarification. Ceramic membranes last longer and can be back flushed. 

Clarification of rough beer, vinegar and pasteurization of clarified beer by cross-flow ultrafiltration are also very common processes utilizing hollow fiber ultrafiltration. As seen in Table 1, an important number of membrane manufacturers specialize in medical and pharmaceutical applications. In pharmaceutical and biotechnology industries, hollow fiber membranes are used for the concentration, separation, and purification of physiological activators such as antibiotics, vaccines, enzymes, proteins and peptides, as well as blood purification (hemofiltration). As a physical barrier for bacteria and viruses, membranes are also a popular option for the production of purified water for hospitals and pharmacies. 

Sterilization and Particle Removal (Beverages). MF has been used extensively in the filtration of wine and beer. It is also currently used in the clarification of cider and other juices. 

A recent survey [30] has shown that in Swiss breweries, the cold break content of beers varied over a wide range, independent of separating procedure. The effects on fermentation, maturation and beer clarification were not significant.. During the course of successive fermentations, the preference of tasting panels shifted from beers where cold trub had not been removed... 

Long-term chemical changes also take place in the maturation vessel such as esterification and certain reductions. During the post-fermenting treatment of beer it is necessary to promote clarification of the beer and, by stabilizing treatment, ensure that turbidity due to chemical precipitation or growth of micro-organisms does not occur. 

Clarification and cold sterilisation of juices, wine and beer Recovery of beer from yeast sediment... 

Furcellaran is also utilized in processed meat products, such as spreadable meat pastes and pastry fillings. It facilitates protein precipitation during brewing of beer and thus improves the final clarification of the beer. 

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