MLF stands for Malolactic Fermentation and is a vital part of winemaking. In the weirdest diet outside Hollywood, a group of bacteria are actually able to live off the energy they derive from turning the strong Malic acid into the weaker Lactic acid. The result for the wine is a drop in acidity of roughly 15%. By-products of the process are lots of gas during the fermentation and a rich, creamy, buttery aroma. MLF softens and adds some complexity to wines, but this is at the expense of some freshness and vibrant fruit character. This makes it undesirable in wines like Riesling and restricted to a blending component in other whites. The fermentation can take a while and the wines needs to be warm and unprotected by sulphur, so it is easy for winemakers to stop it happening. Because MLF always takes place in reds and never in crisp aromotic whites, it rarely gets discussed in these styles. In full-bodied Chardonnays and wines like our Marsanne, its presence and influence is a winemaking choice, so that it when it merits a mention.