Presumed Sexual Isolation in Yeast Populations during Production of Sherrylike Wine.

The three stages in wine production in the Montilla-Moriles region of Spain are (i) fermentation, (ii) film formation in vessels, and (iii) aging, all of which selected three yeast populations. All isolates from the three stages were classified as Saccharomyces cerevisiae. The distribution of characteristics of sugar fermentation (sucrose, galactose, maltose), Li tolerance, and Cu tolerance was different in the strains isolated in the three stages. This finding suggests that sexual isolation in the yeast populations prevents the random distribution of taxonomic characters.