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

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