Malolactic Fermentation [pronunciation: mal-o-lak-tik fer-men-tae-shion-]
The bacterial process by which harsh-tasting malic acid is converted to softer lactic acid (think: the texture of milk) in all red and some white wines. The byproduct of this process is called diacetyl, which adds a buttery texture and flavor to wine.
See also: Méthode Traditionnelle