Increased production of n-propanol in wine by yeast strains having an impaired ability to form hydrogen sulfide

Various strains of Saccharomyces cerevisiae exercised considerable influence on the overall quantity of higher alcohols and their ratios in wine. The influence of the yeast strain is particularly strong for n -propanol and less evident for the other alcohols, especially isoamyl alcohol. There is a strict relationship between the production of highest quantity of n -propanol and the incapacity for the yeast to produce hydrogen sulfide. The results confirm that the production of n -propanol is related to the metabolism of both methionine and threonine.