The increasing ethanol content is a major challenge imposed
by climate change on the production of quality wines. We pro-
pose a strategy for lowering ethanol production during grape
must fermentation by taking advantage of the differences in en-
ergy metabolism among ascomycetous wine yeast species. We
hypothesize that using carefully selected yeast strains the avail-
able oxygen would be taken up by yeast cells for the respira-
tion of a significant fraction of the hexoses present in grape
must. The actual degree of sugar consumption by this pathway,