What is acidity in wine?
Quick answer
Acidity in wine refers to the organic acids — mainly tartaric, malic, and citric — that give wine its freshness, liveliness, and structure. A typical dry white wine has a pH between 3.0 and 3.4, while red wine ranges from 3.3 to 3.6.
Detailed answer
Acidity is what makes wine refreshing. It is that mouth-watering, crisp sensation you feel when you take a sip of Sauvignon Blanc or Champagne — the same feeling you get from biting into a Granny Smith apple or squeezing lemon juice onto your tongue.
All wine is acidic. On the pH scale (where 7 is neutral, like water), most wines fall between 2.9 and 4.0 — roughly as acidic as orange juice. White wines tend to be more acidic (pH 3.0-3.4) than reds (pH 3.3-3.6).
The main acids in wine are tartaric acid (the backbone of wine acidity), malic acid (think green apple), and citric acid (in small amounts). Winemakers can adjust acidity in the cellar using a process called malolactic fermentation (MLF), where bacteria convert sharp malic acid into softer, creamier lactic acid. This is why a buttery Chardonnay from Burgundy feels rounder than a steely Chablis — the former has undergone MLF, the latter usually has not.
Climate plays a major role. Grapes grown in cool regions like Champagne, the Loire Valley, or Germany's Mosel retain more acidity because cooler temperatures slow sugar accumulation and preserve the acids. Warm-climate wines from regions like southern Australia or California's Central Valley tend to have lower acidity and feel softer and riper.
Why does acidity matter at the dinner table? It makes wine a brilliant food partner. High-acid wines cut through rich, fatty dishes (think Champagne with fried chicken, or Sancerre with goat cheese). They also cleanse your palate between bites, leaving you refreshed and ready for the next forkful.
Finally, acidity is a natural preservative. Wines with high acidity — great Riesling, Chenin Blanc, Barolo — tend to age the longest, sometimes for decades. So when you see an old wine in a shop, check whether the grape is known for high acidity. If so, chances are good that the wine is still alive and vibrant.