AbstractA survey has been made of a selection of the lactic acid bacteria occurring in 12 samples of yeast and 9 samples of beer from British breweries. Strains of 8 known species were identified and these includedLactobacillus buchneri, Lb. bifidus, Lb. leichmanii, Lb. plantarumandStreptococcus cremoris, none of which has hitherto been detected in beer. In addition, three rod‐shaped organisms which were isolated proved to be the type cultures of three new species ofLactobacillus.Five cocci which were isolated were found to be related toPediococcus damnosusvar.salicinaceusMees and have been classified as strains of this species. These organisms had very small cells, those ofPed. damnosusvar.salicinaceusitself being relatively much greater in diamete