The apparent adaptation of wine yeast to sulfite was examined using an inoculation of precultured cells with or without the addition of preculture broth. When precultured cells were used as the inoculum, the maximum concentration of sulfite permitting yeast growth was identical, whether the preculture medium contained sulfite or not. On the other hand, when the precultured cells and 5 % or 10%(v/v) of the preculture broth were added to fresh medium, the yeast grew in a higher concentration of sulfite than in the absence of the added preculture broth. When concentrations of acetaldehyde and pyruvic acid identical to the preculture medium were added to the fresh medium, the yeast grew in the medium containing the same concentration of sulfite as in medium with the added preculture broth. Thus, the sulfite binding activities of carbonyl compounds, such as acetaldehyde, pyruvic acid and α-ketoglutaric acid (2-oxoglutaric acid), seem to cause this adaptive effect.