SOME EFFECTS OF LACTOBACILLUS CONTAMINATION IN SCOTCH WHISKY FERMENTATIONS

Abstract

The growth of representative strains of lactobacilli in a laboratory scale distillery fermentation has been examined. Some strains were particularly deliterious to the fermentation and were responsible for reducing the final pH, increasing the final gravity and reducing the alcohol concentration in fermented wash. The effects of varying degrees of infection by one deliterious strain and one innocuous strain were studied in more detail. Spirit yield depended on strain and inoculum size. In all cases the concentration of lactic acid was increased and the balance of other organic acids was disturbed by the presence of the bacteria. 1988 The Institute of Brewing & Distilling