Malolactic Fermentation is the conversion of malic acid to lactic acid by bacteria from the lactic acid bacteria family.Lactic acid is less acidic than malic acid, which in turn decreases acidity and helps to soften and/or round out some of the flavors in wine.alolactic Bacteria. WLP675 Malolactic Cultures. Malolactic Fermentation is the conversion of malic acid to lactic acid by bacteria from the lactic acid bacteria family. Lactic acid is less acidic than malic acid, which in turn decreases acidity and helps to soften and/or round out some of the flavors in wine.