Chemistry

If you’ve ever taken a wine class or have been around, say, Chardonnay drinkers, the term “malolactic fermentation” may have been on the wine-soaked tongues of your peers. It also may have been referred to by its nickname, “malo,” as in, “Wow, I’m totes getting some serious malo on this Chard.” It’s a term used to explain a buttery sensation on the nose and palate. It’s also a natural occurrence in winemaking that adds to and sometimes decreases the quality of the wine you’re sipping. Let’s get into the mellowness of malo, man.

Malolactic fermentation is the conversion of malic acid (a natural acid that exists in grapes) to the softer, comfier lactic acid. Lactic, latte, milk, butter . . . getting a picture here? This is a natural conversion that is accomplished by introducing the presence of lactic acid bacteria, which often live in wineries. Let’s break it down further: During the fermentation process, where yeast cells are munching on sugar and converting it to alcohol and carbon dioxide, it’s a hot business; inside that fermentation tank, the temp is rising to upwards of 85 degrees Fahrenheit. Once that wonderful mess finishes the throes of the roil and toil, lactic acid seeks out the malic acid and attaches itself, thus beginning malolactic conversion. Now for some fun, geeky science stuff:

COOH-CHOH-CH2-COOH→COOH-CHOH-CH3 + CO2
malic acid→lactic acid + carbon dioxide

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That’s what the conversion looks like on paper, but what we really care about is what it means for the wine. Red and white wines are put through this conversion process in order to soften the wine’s acidity level. Malic acid, along with the other important acid, tartaric, are perceived as ripe or austere. The lactic conversion creates a buffer among the sharper elements of a wine, thereby creating a sense of butteriness on the nose and palate.

While all wine can go through malolactic fermentation, winemakers can stop the process midway, before the lactic conversion overly imparts buttery flavors.

The problem that can arise, and where things get a little sticky, is when winemakers take the process too far and create too much malo in the wine; too much malo will overpower all of the other sexy subtleties the glass wants to put in your face. Chardonnay is the most susceptible to this process, which is why after the toast and vanilla notes (oak influence) you can get that hint of funny banana cream. If that banana cream is all you smell then the wine is out of balance and the winemaker was unable to get his or her malo under control. This problem will be blatantly apparent in unoaked Chardonnays (no vanilla, no toast). But, when it’s done right, instead of a big alcoholic butterball, there’s just a crisp, round, juicy full white wine with subtle notes of buttery goodness.

Are you totes getting malo on this post?