Thursday, June 14, 2007

Wine Education Series

Malolactic Fermentation (COOH-CHOH-CH2-COOH--->COOH-CHOH-CH3 + CO2)


You hear this term thrown around a lot in wineries and it is often a question I ask the tasting room staff or if lucky enough the winemaker if the process has been performed on certain white wines.

So what exactly is Malolactic Fermentation (MLF)? Well it is the conversion of malic acid which is naturally occurring in wine that has just been made into lactic acid and as a bi - product carbon dioxide is also produced. Now the misconception is that MLF is actually not a fermentation at all, even though carbon dioxide is generated during the process.

Now why would winemaker's feel the need to perform MLF on a wine. Well the main reason is the need to lower the total acidity of a wine. Lactic acid is much softer than Malic acid and therefore if a wine is too acidic after fermentation, MLF can be done to lower the acidity and soften the wine. If you have ever had a Chardonnay or other wine that had a buttery note or flavor to it, then that wine has gone through MLF, because the chemical diacetyl is also a bi product of MLF and this cause the buttery notes in wine.

Now over the years as "better" wine making practices have been developed MLF is done to prevent any possibility of it happening in the bottle, although this rarely happens any more with filtered wines that are filtered with a sterile filter.

For any more info on Malolactic Fermentation shoot me an email - I'd be happy to discuss.

Enjoy the beautiful weekend with some beautiful wine!

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