Last time we looked at acidity levels in wine that are measured on the pH scale and in terms of grams of acid per liter (Total Acidity). While Total Acidity is a measure of the concentration of acids in a wine, the pH level tells you how intense those acids will be.
So, let’s now look a bit more into the acids in wines.
There are four primary types of acids in wines - tartaric acid, malic acid, citric acid, and lactic acid.
“Wine Diamonds” on a Cork
Tartaric acid is the primary acid in wine grapes. But, only about half the tartaric acid in a grape is soluble in wine. The rest tends to attach itself to pulp debris, tannins, and pigments during the fermentation and aging process. And, sometimes that undissolved tartaric acid crystallizes in the wine. That’s what “wine diamonds” are. Those little broken-glass-looking shards you sometimes find on a cork or in your wine. But, don’t worry, they’re completely harmless.
Now, let’s move on to Malic acid which is the second most prominent type of acid in wine grapes. It too is produced as part of the grape growing process. But, Malic acid in grape vines decreases as vines grow older and the grapes ripen.
If malic acid is too high, winemakers can initiate a process called malolactic “fermentation” (MLF) which converts some of the malic acid (like that of a tart green apple) to the more mild lactic acid. This conversion gives a wine a buttery, creamy mouthfeel. You may know lactic acid as the primary acid present in a lot of fermented products, like yogurt, kefir, and sourdough bread.
Malolactic Fermentation is not actually a fermentation. It’s just a chemical process that converts one type of acid to another type of acid. So, it is more correctly a Malolactic Conversion, not a fermentation.
And, while most red wines undergo malolactic conversion, only some white wines, notably Chardonnay, undergo this process.
If you don’t care for highly acidic flavors in wines, try a full-bodied red wine such as Cabernet Sauvignon, Merlot or a Syrah. But, if you love a crisp, refreshingly tart flavor, look for light-bodied white wines such as Albariño, Sauvignon Blanc, Riesling or a brut sparkling wine.