AbstractIn brandy base wines, no sulphur dioxide is used and it therefore is ideal for the proliferation of lactic acid bacteria. Aspart of an extensive taxonomic survey within the ecological framework of South African vineyards and wineries, and theinfluence of naturally occurring lactic acid bacteria on the quality of wine and brandy, a total of 54 strains were isolated fromgrape juice and at different stages of brandy base wine production. The strains were identified using numerical analysis oftotal soluble cell protein patterns, 16S rRNA sequence analyses and polymerase chain reaction (PCR) using species-specificprimers. The predominant species was Oenococcus oeni (22 strains), but Lactobacillus brevis (8 strains), Lactobacillusparacasei (8 strains) and Lactobacillus plantarum (6 strains) were also isolated frequently. Many of the O. oeni strains wereisolated from brandy base wines after completion of spontaneous malolactic fermentation (MLF). The Lactobacillus spp.were isolated from all the different stages of brandy base wine production. Lb. plantarum was the dominant species in thejuice, but disappeared during the later stages of production. However, Lactobacillus hilgardii, Lb. brevis and Lb. paracaseiwere also isolated from base wine after spontaneous MLF. Strains identified as Lactobacillus vermiforme were isolatedduring the alcoholic fermentation and after MLF have been completed. Total soluble cell protein patterns grouped O. oenistrains into two phenotypic groups. Two phenotypic clusters have also been identified for the Lb. brevis isolates. The Lb.paracasei isolates all grouped in one cluster. This is the first report of the presence of Lb. paracasei and Lb. vermiforme inbrandy base wines. The presence of the Lactobacillus spp. could be correlated to the decrease in quality of the base wine anddistillate, while O. oeni strains were found to have a more favourable influence on the quality of base wine and distillates.These results shed some light on the ecology and oenological influence of lactic acid bacteria (LAB) on the quality of SouthAfrican brandy.