The Effect of Fumaric Acid on Malo-Lactic Fermentation in Wines from Warm Areas

Abstract

Wines made from grapes from warm areas such as the San Joaquin Valley would seldom seem to benefit from malo-lactic fermentation. Not only is acidity lost but off-odors and off-flavors can develop which are sometimes difficult to remove. Most wines from these areas are sold young, without aging, and part of their value is their fresh fruitiness.

Fumaric acid has been shown (3, 8) to be effective in delaying or inhibiting the growth of malo-lactic bacteria in wine. Earlier work (5) had indicated that quality difference in wines might depend on the species of malo-lactic bacteria present.

This paper demonstrates that routine addition of fumaric acid at the time of the first racking, along with a normal addition of sulfur dioxide, will in general improve wine quality significantly by inhibiting malo-lactic fermentation as well as adding needed acid to the wines. In addition, the usual recommended malo-lactic strain (Leuconostoc oenos ML-34) was tested to see whether it did improve wine quality over that obtained by allowing a natural flora to develop.