Alterations in beer cellar operations to prevent dissolved oxygen.

Selles, J.F.

Abstract
In view of the known role of oxidative reactions in the deterioration of beer over time, a scheme to minimize the possibilities for the dissolution of oxygen in beer by radical changes in processing is described. The proposed process involves passing the whirlpooled and cooled wort through a kieselguhr filter before pitching. Fermentation is carried out in a "Nathan" type cylindro conical tank which incorporates facilities for removing the yeast crop and undesirable volatile fermentation by-products without any contact between the tank contents and the air. There is no separate maturation process, as diacetyl removal takes place at the end of primary fermentation. Proteolytic enzyme preparations are used to break down any large protein molecules in the beer in the fermenter. The beer is then centrifuged, carbonated and filtered. If it is necessary to hold the beer in tanks before filtration, the tanks must be filled with water and purged of that water with carbon dioxide before being filled with beer, making it necessary to install additional tanks for the recovery of the water and carbon dioxide used. The bright beer tank receives beer directly from the filter and discharges it straight to the packaging line. It is anticipated that the implementation of this scheme should reduce the time and costs involved in beer production as well as prolonging the shelf life of the beer produced.
Keywords : beer fermentation filtration inhibition oxidation stabilisation wort