A rapid epifluorescence staining method using the LIVE/DEAD® BacLight™ Bacterial Viability kit was applied to differentiate both viable and total counts of acetic acid bacteria in vinegar fermentation. The results obtained were compared with those from other measurement techniques: 4′,6-diamidine-2phenyl indole (DAPI) and 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) and colony counts. BacLight total counts were comparable to DAPI (differing by <3.5%). BacLight viable counts were similar to CTC counts but considerable higher than colony-forming cells in plates.