Controlled Simultaneous Deacidification and Alcohol Fermentation of a High-Acid Grape Must Using Two Immobilized Yeasts,Schizosaccharomyces pombeandSaccharomyces cerevisiae

Saccharomyces cerevisiae W3 and Schizosaccharomyces pombe IFO 0358 were separately immobilized in double-layer Ca-alginate fibers. White wines were made from a high-acid Ezerfürtü white must using the fiber-immobilized yeasts in different combinations. The best results in terms of wine quality, especially in acidity and lack of off-odors, were obtained when immobilized Schizosaccharomyces pombe fibers were removed as soon as the malic acid in the fermenting must had decreased to a desirable content, and then allowing the fermentation to proceed to completion by the addition of the immobilized Saccharomyces cerevisiae fibers. The use of gel fibers with the two immobilized yeast strains permitted easy and effective control of both deacidification and alcohol fermentation. The white wine made by the method had only a small amount of sediment, little distinct off-flavor, and less than 103free yeast CFU/mL in the must at the end of the fermentation.