Effects of Certain Vitamins on Growth and Fermentation Rate of Several Commercial Active Dry Wine Yeasts

Abstract

Three commercial dry yeast preparations were used to study the effects of vitamins on growth and fermentation rates of model grape juice solutions under simulated winemaking conditions. The yeasts used were Saccharomyces cerevisiae, Montrachet, Pasteur, and Epernay II. Certain vitamins or combinations of vitamins, including inositol, pantothenate, pyridoxine, thiamine, and biotin, were omitted or added at reduced levels. When certain vitamins were left out, the total viable cell counts were reduced. Omission of other vitamins had little effect. One of the more commonly used yeasts by the California wineries, Saccharomyces cerevisiae Montrachet, was most dependent on certain vitamins. Fermentation rates were also affected and not always in direct proportion to viable cell counts. Biotin was critical in improving the efficiency of fermentation, but at concentrations lower than normal for grape juices. Similarly, pantothenic acid requirements were much less than normally present in natural grape juice.