Malolactic fermentation (often abbreviated as MLF) is a secondary fermentation process in winemaking that converts sharp, tart malic acid into softer, creamier lactic acid. This transformation takes place after the primary alcoholic fermentation, during which yeast converts sugars into alcohol. MLF is carried out by specific bacteria, typically from the species Oenococcus oeni.
The purpose of malolactic fermentation is to reduce the wine’s acidity and enhance its texture, making it smoother and rounder on the palate. Wines that have undergone MLF often exhibit a buttery or creamy texture, which is especially noticeable in some styles of Chardonnay. In red wines, malolactic fermentation is almost always done, as it helps soften the tannins and integrate the flavors.
While MLF occurs naturally in some wines, winemakers can choose to either encourage or prevent it, depending on the style they want to achieve. For example, a winemaker producing a crisp, fresh white wine like Sauvignon Blanc may opt to prevent malolactic fermentation to preserve the wine’s bright acidity. On the other hand, winemakers crafting a rich, full-bodied Chardonnay may encourage MLF to give the wine a creamy mouthfeel and buttery flavors.
The process typically takes a few weeks to complete and requires careful temperature control and monitoring. Some wines undergo partial malolactic fermentation, where only a portion of the wine is allowed to ferment in this way, striking a balance between acidity and softness.
Malolactic fermentation is an important tool in a winemaker’s arsenal, offering flexibility in creating different textures and flavor profiles, particularly for white wines and some reds.
Curious about more wine terms and insights? Visit our Wine Wiki section and explore the basic wine terms for expert definitions and tips!
English