Laboratory Studies of the Malo-Lactic Fermentation

Abstract

The experiments describe laboratory work done early in 1959 which lead to some of the commercial fermentations reported by Webb and Ingraham (8). The addition of Wine, containing yeast and lactic acid bacteria, to grape juice induced both an alcoholic and malo-lactic fermentation. Further serial inoculation was found to be impractical. There was a prohibitive rise of volatile acidity even though substantial amounts of sulfur dioxide had been added to the samples. The responsible lactic acid bacteria was isolated from the wine and used to induce a malo-lactic fermentation in grape juice undergoing an alcoholic fermentation. It was found that a certain red grape concentrate had to be sterilized with heat in order to allow the fermentation. Two pentoses were added to a 6 month old wine in an effort to induce the malo-lactic fermentation which was not successful. Various yeasts and various lactic acid bacteria were used in a number of trials to find their effect on the fermentation and on the product. The influence of the choice of microorganism on the wine quality was estimated with some simple experiments.