What is Malolactic Fermentation?

Published by Tamara Harrison - 27th May 2019

Have you ever wondered how some wines have a creamy taste? It’s the process of Malolactic Fermentation. Talented WA winemaker Cathy Howard from Boots & All loves sharing her wine knowledge with us, she’s previously touched on “What is a Vigneron?” and now she is back with Malolactic Fermentation.

Malolactic Fermentation (AKA ‘MLF’ or ‘malo’ in winemaker speak) is the process that gives both red and white wines a richer and creamier texture.

MLF is the step in the winemaking process which almost all red wines and some whites, such as Chardonnay, go through after the alcoholic ferment is complete. It is keeping me busy in the winery right now, as I spend a lot of time warming tanks and barrels of wine to keep them all at 18 to 20 degrees. 

Malic acid is a tart, sour tasting acid (think about biting into a fresh granny smith apple), whereas lactic acid is a soft, creamy tasting acid (think about taking a sip of milk). Bacteria carry out the fermentation, consuming the malic acid and producing lactic acid. This process ensures the wine tastes softer, smoother, and less acidic.

Cheers, Cathy.