Kaffircorn malting and brewing studies. II.—Studies on the microbiology of Kaffir beer

Abstract

Abstract The three main microbiological conversions in the production of kaffir beer have been studied, viz.: the souring of the mash by lactic acid bacteria, the alcoholic fermentation of the wort by a variety of yeasts generally present on the malt used in the conversion and, finally, the spoilage due to volatile acid formation. It was found that in breweries where no temperature control was practised during souring, a very heterogeneous lactic acid microflora developed. Eight species were recognized. In the subsequent alcoholic fermentation twenty different yeast species were isolated from beers. Saccharomyces cerevisiae, Candida krusei and Kloeckera apiculata were found to be the predominant species. The spoilage due to excessive acetic acid formation was found to be caused by the development of the common malt and beer Acetobacter species.