Selective breeding of Saccharomyces cerevisiae to increase glycerol levels in wine

Abstract

Glycerol in wines is at levels of 1 to 10 g/l and improves their body. To breed wine yeast for increased glycerol production, we crossed yeast isolated from natural fermentations with a commercial strain. The average glycerol concentration of 187 wine yeast strains was 4.2 g/l. Strain Ba25 had the highest glycerol production and a spore clone of Ba25 was crossed with one of Premier Cuvée, the best commercial strain, by spore-spore pairing and this was repeated three times. Several of the spore clones produced >15 g/l of glycerol. Glycerol and ethanol levels were inversely related.