Malolactic Fermentation

A secondary fermentation process in which naturally-occurring malic acid, which is typically tart, is converted to lactic acid. This softens the acidity of the wine and creates a rounder flavor profile. The process is almost always utilized for red wines and sometimes for whites, most typically Chardonnay. The fermentation process also creates diacetyl as a by-product, a compound that imparts a buttery aroma and flavor. Fairly unnoticable in red wine, it's very apparent in whites, and some winemakers will utilize a third process to remove the diacetyl.