Etude d'un nouveau procédé de déclenchement de la fermentation malolactique
Abstract
A method is described, by wich the malolactic fermentation is induced through direct inoculation with an industrial preparation of L. plantarum (CHL2). When inoculated into must, this homofermentative lactobacillus metabolizes very little sugar, and is unable to produce acetic acid. The inoculated population of bacteria has a high malolactic activity even at low pH values, which is closely related to cell viability. The decarboxylation of malic acid starts immediately after inoculation and proceeds at a high rate during the first days of alcoholic fermentation. As the alcohol concentration rises, the lactobacilli are gradually eliminated, so inoculation with the malolactic culture has to be done very early in the vinification process, in order to achieve a complete malolactic fermentation. At the end of alcoholic fermentation, the malolactic fermentation is finished, and the bacterial inoculum has been completely killed of.
The efficiency of this new process is demonstrated in laboratory experiments and field trials with different types of must and different vinification procedures. The advantages of the method, which the winemakers would particularly appreciate, include the direct inoculation mode and considerable gain in terms of production time.