A Review and some Studies of the Effect of Sulfur on the Formation of Off-Odors in Wine

Abstract

Sulfur dioxide in excess of 100 ppm in fermenting media may cause hydrogen sulfide off-odors. Elemental sulfur, as low as 5 ppm, will definitely provide residual hydrogen sulfide at the end of fermentation. Pumping over and periodic aeration will minimize the danger of hydrogen sulfide.

Most of the hydrogen sulfide formed during fermentation is lost to the atmosphere, and this is facilitated by the sweeping action of carbon dioxide.

Slow, cold, anaerobic fermentations encourage residual hydrogen sulfide in the wine.

Sulfur applications in the vineyards are responsible for the presence of elemental sulfur in grape juices; but in wineries where the burning of sulfur wicks in barrels and tanks is still practiced, this will be another source of elemental sulfur which is chemically reduced to hydrogen sulfide during fermentation.

From this investigation it appears that the grower, especially in the coast counties, should avoid sulfuring very late in the season.