In order to convert the grape’s natural sugars to alcohol, wine must go through fermentation.  But a winemaker may also decide to put the wine through a second fermantation, called malolactic fermentation (malo, for short). Malolactic is almost always used in red wines but is sometimes used on whites, most often on Chardonnay. Malolactic fermentation converts the malic acid (tart, like a green apple) to lactic acid (mild, creamy). This calms the acidity and can give the wine a buttery, rich mouthfeel.