What effect does malolactic fermentation have on wine?

Malolactic fermentation is a crucial process in winemaking, particularly in red wines and some white wines like Chardonnay. This secondary fermentation occurs after the primary alcoholic fermentation and involves the conversion of sharp malic acid, which is naturally found in grapes, into softer lactic acid. This transformation not only reduces the overall acidity of the wine, providing a smoother and more rounded mouthfeel but also introduces desirable buttery flavors, often characterized as creamy or smooth as a result of compounds produced during this fermentation process.

The buttery flavors arise primarily from the production of diacetyl, a compound that can impart a richness and complexity to the wine, enhancing its appeal and balance. As a result, wines that undergo malolactic fermentation tend to be more approachable and complex in flavor, making this process particularly valued in the creation of certain wine styles. This transformation makes malolactic fermentation a significant step in developing the sensory profile of various wines.