Beer is not a very appropriate medium for the development of bacteria due to its characteristics, such as the low quantity of available nutrients, the presence of alcohol, carbon dioxide and sulphur dioxide, as well as low conservation temperatures. Beer filtration and pasteurization phases also contribute to the stabilization of the product against microorganisms.

The number of genera and species which usually contaminate it is limited. As is the case with wild yeasts, the contaminating bacteria cause turbidity and generate anomalous smells and bouquets. Lactic acid bacteria are the only Gram-positive ones that cause serious problems within beer-producing industries. The frequently found ones only belong to two genera: Lactobacillus and Pediococcus. Wild yeasts are also frequent contaminants in beer production.

Culture media for Bakery products


In order to guarantee a process free of microorganisms, equipment and facilities should be kept in a perfect state of hygiene since contaminating elements almost always locate themselves in tanks, pipes, hoses, etc. It is also necessary to subject all equipment and raw materials including water, malt, triturates, hops, etc., to these controls.

Culture media specific for beer follow: