Beer treatment

M R. CLELAND, J. MEISSNER, A.S. HERER, E.W. BEERS, Treatment of Foods with High-Energy X rays, American Institute of Physics, AIP Conference Proceedings, Vol. 576, pp. 783-786, 2001. 

The carbon dioxide can of course be recovered readily from the enclosed vessels. For one unit weight of sugar, about half this weight is theoretically recoverable as carbon dioxide and, considering the cost of the gas and the great use for it in the post-fermentation period of beer treatment, the escape from open fermenters appears to be an expensive waste. In practice, the percentage of carbon dioxide recovered is rarely above 50% of the theoretical (see Chapter 20). There is, however, considerable debate on the economics... 

Fig. 20.9 A beer and yeast recovery system. 1. Fermenter 2. Beer clarifier 3. Surge tank 4. Yeast suspension tank 5. Filter aid mixer 6. Yeast (autolysis) tank 7. Rotary vacuum filter 8. Top feed applicator 9. Precoat applicator 10. Yeast suspension spray 11. Defoamer 12. Vacuum pump 13. Beer recovery tank 14. Pasteurizer 15. Yeast drier A. Wort preparation B. Beer treatment C. Dried yeast. (Based on drawing of Alfa-Laval Ltd.)...

Self-cleaning clarifiers, in which the solids are discharged at intervals while the centrifuge is operating at full-speed (Fig. 20.12). They are available for both wort and beer clarification with throughputs of up to 600 hl/hr (370 brl/hr). The same machines used for beer recovery from fermenters and tank bottoms operate at up to 40 hl/hr (25 brl/hr). Many of these machines used for beer treatment are hermetically sealed so that neither carbon dioxide is lost nor oxygen taken up. 

As mentioned above, beer treatments may be classified as additive or adsorptive. Ascorbic acid and potassium metabisulphite are permitted additives in most countries. Other additives used include tannic acid and proteolytic enzymes. Addition of tannic acid to beer had no effect on the... 

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