Sixty-four strains of Lactobacillus were isolated from fermentation samples from 23 malt whisky distilleries located in the major whisky producing regions of Scotland. The strains were assigned to 26 ribotype patterns. Strains of some ribotype patterns were widely distributed and recovered from distilleries throughout Scotland, while strains representing other ribotypes were particular to a specific region or even a certain distillery. Repeated sampling of a single distillery over a 12 month period showed that the range of bacteria present, as indicated by ribotyping, was stable, but was influenced by changes in malt supply and the period of closure for annual maintenance. Partial 16S rDNA sequence analysis of ribotype representatives revealed Lactobacillus brevis, Lactobacillus fermentum, Lactobacillus paracasei and Lactobacillus pentosus as the major species present in the distilleries; however, four isolates could not be identified by this procedure. Determination of the full 16S rDNA gene sequence from one of these isolates (strain R7-84) revealed >98.5% similarity to Lactobacillus buchneri and its phylogenetic neighbours. DNA from two other strains showed greater than 70% hybridization to DNA from R7-84 under non-stringent renaturation conditions and DNA from strain R7-84 shared less than 65% hybridization with members of the L. buchneri group. It is proposed that these three strains should be placed in a new species for which the name Lactobacillus ferintoshensis represented by the type strain R7-84(T) is suggested.