Beer quality can be compromised by the growth of certain lactobacilli, in particular Lactobacillus brevis and Lactobacillus plantarum, and various strategies have been used to control such bacterial spoilage. Biocontrol by means of bacteriophage is a reemerging approach for the suppression of spoilage bacteria in food and beverage matrices. A virulent phage capable of infecting L. brevis beer-spoilage strains was isolated and morphologically assessed by electron microscopy. The myophage SA-C12 was shown to be stable in beer and capable of controlling the growth of its host, L. brevis strain 56, in commercial beer. The results of this study indicate that bacteriophage-based treatments may be used as an alternative and natural strategy for the control of bacterial contamination of beer.