Malolactic fermentation (MLF) is not a true fermentation but a bacterial conversion. Lactic acid bacteria (Oenococcus oeni and others) convert the grape's sharp malic acid into softer lactic acid. The effect in the glass is striking: the wine becomes rounder and creamier, the sharpness perceived as 'green' disappears and is replaced by a buttery quality. In red wine MLF almost always occurs — it softens the tannin structure and increases stability. In white wine it is a stylistic choice. Chablis and German Rieslings often avoid MLF to retain their razor-sharp acidity and minerality. Burgundian Chardonnay almost always undergoes MLF, producing the characteristic butter and cream note.