Glycerol is the major fermentation product after
ethanol and carbon dioxide in wines. It is the most
prominent of wine polyols and is produced from the
reduction of dihydroxyacetone phosphate to glycerol-3-
phosphate (G-3-P), a reaction catalyzed by G-3-P
dehydrogenase and then to glycerol by glycerol-3-
phosphatase. During alcoholic fermentation, the main
roles of glycerol are to equilibrate the yeast endocellular
oxidation/reduction potential or NAD/NADH balance
[1] and to act as an osmoregulatory metabolite in
response to the high osmotic pressure of the sugar
solution in the fermenter [2]. Glycerol is naturally found
in wines, with about 8 g of glycerol/100 g of ethanol [1].
Glycerol concentrations in wines vary between 1 and 10
g/l [3,4].