Influence of Pre-culture Conditions on the Ability of Leuconostoc oenos to Conduct Malolactic Fermentation in Wine

Abstract

Most industrially freeze-dried malolactic starters must undergo a pre-culture or reactivation process. This step permit a good implantation into wine. Variables of pre-culture conditions studied were the duration of the reactivation process and initial reactivated cell population. Reactivation in half-strength wine followed by growth in a medium with 75% wine allowed a gradual readjustment of bacteria to counterbalance the effect of wine components. The inoculum of the pre-culture media has to be, at most, 10⁷ cfu/mL so that malic acid degradation follows cellular proliferation. The utilization of malic acid in the pre-culture medium determines the time to collect bacteria for their inoculation into wine.