A Gram-positive rod was isolated from a commercial grape wine undergoing a sluggish/stuck alcoholic fermentation. The organism produced L-lactic acid from glucose, possessed weak catalase activity, and fermented relatively few carbohydrates, i.e. glucose, fructose, sucrose, raffinose (weakly) and mannitol. The 16S rRNA gene sequence analysis revealed that the isolate was phylogenetically a member of the genus Lactobacillus and formed a distinct subline within the Lact. casei cluster of species. Based on phenotypic and phylogenetic evidence, a new species is proposed, Lact. kunkeei. The type strain of Lact. kunkeei is ATCC 700308.