RECENT ADVANCES IN THE MALTING AND BREWING INDUSTRY

Brewing is often mentioned as a typical example of traditional or old biotechnology, because of its extremely long history. However, the mod ern malting and brewing industry applies a whole spectrum of new techn ical, biochemical, microbiological and genetic inventions. Examples of contemporary achievements can be found along the whole production cha in from barley to beer. Malted barley contains all the enzymes needed for all-malt brews. Exogenous microbial enzymes may be needed when usi ng high amounts of cereal adjuncts. Transgenic barleys and proper star ter cultures in malting offer interesting new possibilities to ensure balanced enzyme activities and to avoid harmful Fusarium contamination s. High gravity brewing, automated mash filters and hop extracts produ ced with super-critical or liquid carbon dioxide have been adopted by the industry. Continuous bioreactors with immobilized yeast are alread y used for maturation of beer. The residence time in the bioreactor is only 2 h, whereas several weeks are needed for traditional lagering. Continuous main fermentation with immobilized yeast is the next step. Several genetically modified brewer's yeasts have been constructed, e. g. yeasts encoding alpha-acetolactate decarboxylase and super-floccula ting yeasts. The brewing industry is now waiting to be assured of cons umer approval. (C) 1998 Elsevier Science B.V. All rights reserved.