After the yeast-induced alcoholic fermentation, most red wines and some whites undergo a second fermentation, induced this time by bacteria. This fermentation takes place in red winemaking systematically, and in a few white wines. The bacteria transform sharp-tasting malic acid into softer lactic acid, making the wine taste softer, and greater flavour complexity also develops as the malolactic fermentation progresses. Wines are more stable and less acidic after malolactic fermentation.

Fermentation - the bacterial process that converts the harsh Malic acid into the softer Lactic acid. While it can occur naturally, it is mostly induced by winemakers for all red wines and some white wines.

A secondary fermentation occurring in most red and some white wines used to convert the grape’s primary malic acid into a softer lactic acid.