Extract recovery from surplus yeast.

Potgieter, D., Parsotam, R. and Perry, M.

Abstract
Trials of a Westfalia SC120-36-777 centrifuge for the recovery of beer from surplus yeast, carried out by South African Breweries, are described. It was found that diluting the yeast suspension with chilled, deaerated, carbonated brewing liquor before centrifugation can increase the recovery rate. Temperature increase and oxygen pickup during centrifugation were very low, and no contamination or loss of yeast viability could be found. The recovered beer was analysed and compared both with beer from the main production stream and beer obtained from cropped yeast slurry by very gentle filtration. The latter proved to be very similar to the centrifugally recovered beer. The addition of 5% recovered beer to production beer was found to have no significant effects on flavour, colloidal stability or foam quality.
Keywords : beer brewers' yeast centrifugation quality recovery