The role of acetic acid bacteria in brewing and their detection in operation

Abstract

Acetic acid bacteria (AAB) are often considered a threat of the past because today’s equipment allows to perform post-fermentation processes under greatly reduced level of oxygen. This paper deals with the current importance of AAB in brewing. The risk of contamination as well as functional role in spontaneously fermented sour beers is reviewed. The main harmful effect of AAB lies in the direct spoilage of draft beer and formation of biofilms, most often in dispensing systems. On contrary AAB seems to be indispensable in the case of sour beer production. A key issue of AAB in brewing environment is their (early) detection and identification. Therefore, part of this study is devoted to both the latest sophisticated methods and also those of traditional cultivation. which are still prevalent in operating laboratories due to their cost and easy implementation. Finally, the experimental and pictorial material is added as a guide for operations that have less experience with AAB.