Characterization of wine yeasts for ethanol production

Summary Selected wine yeasts were tested for their ethanol and sugar tolerance, and for their fermentative capacity. Growth () and fermentation rates () were increasingly inhibited by increasing ethanol and glucose concentrations, flor yeasts being the least inhibited. Except in the latter strains, the ethanol production rate was accelerated by adding the glucose stepwise. The best fermenting strains selected in laboratory medium were also the best at fermenting molasses. Invertase activity was not a limiting step in ethanol production, being accelerated by supplementing molasses with ammonia and biotine, and by cell recycle.