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

¹ Institute of Enology and Viticulture, Yamanashi University, Kofu, Yamanashi 400, Japan
² Tokachi-Ikeda Viticulture and Enology Experimental Station, Ikeda, Hokkaido, Japan
³ Institute of Applied Biochemistry, University of Tsukuba, Tsukuba 305, Japan.

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.

Key words: alcoholic fermentation, deacidification, Saccharomyces cerevisiae, Schizosaccharomyces pombe, immobilized yeasts

Submitted on March 13, 1992