Acidity in Wine

What is acidity in wine?

Acidity is one of the fundamental components of wine and is crucial for its freshness, vibrancy, and ageing potential. It is what gives a wine its "bite" and prevents it from tasting flat or dull. You perceive acidity in wine as a tingling, refreshing sensation on the tongue and the sides of the palate — it stimulates salivation and makes you reach for the next sip.

Which acids occur in wine?

Several natural acids are found in wine:

Tartaric acid is the most important and most stable acid in wine. It occurs almost exclusively in grapes and is preserved throughout the entire winemaking process. At cold temperatures, tartaric acid can settle as wine crystals (potassium bitartrate) at the bottom of the bottle or on the cork — this is completely harmless and a hallmark of minimally processed wines.

Malic acid is the second major acid in grapes. It tastes sharper and greener than tartaric acid — similar to a green apple. During malolactic fermentation, malic acid is converted into softer lactic acid, making the wine rounder.

Lactic acid is produced through malolactic fermentation and tastes noticeably softer and creamier than malic acid. Most red wines and many premium white wines undergo this "second fermentation" to round off acidity.

Citric acid occurs naturally in small amounts and may be added in some wine regions for acidity correction.

The role of acidity in flavour

Acidity is the counterpart to sweetness and ensures balance in wine. A wine with high residual sugar needs sufficient acidity to avoid tasting cloying — which is why German Rieslings work so well: the combination of sweetness and vibrant acidity makes them remarkably harmonious.

In dry wines, acidity provides structure and freshness. It lifts the fruit aromas and makes the wine more lively. A wine with too little acidity tastes flat and dull; a wine with too much acidity seems aggressive or green.

Acidity and climate

Climate has an enormous influence on acidity levels:

Cool climate zones (Germany, northern France, New Zealand) produce wines with high acidity. The grapes ripen more slowly, retain more acid, and simultaneously develop fine aromas.

Warm climate zones (southern Spain, California, Australia) lead to lower acidity levels. The grapes lose acidity more quickly during ripening, resulting in softer, rounder wines — sometimes at the expense of freshness.

Acidity in food pairing

Acidity is a wine's best friend at the table! It cuts through fat, cleanses the palate, and enhances the flavours of food. This is why high-acid wines pair superbly with:

• Fatty dishes: The acidity cuts through creaminess (Riesling with cream sauce)
• Fried foods: Cleanses the palate between bites
• Acidic dishes: The wine should have at least as much acidity as the food (Sauvignon Blanc with lemon pasta)

Tip for wine selection

If you prefer high-acid wines, look for:

• Grape varieties such as Riesling, Sauvignon Blanc, Grüner Veltliner, Albariño (white) or Nebbiolo, Sangiovese (red)
• Cooler wine regions (Germany, Loire, Alto Adige, northern Italy)
• Younger wines (acidity decreases with age)

If you prefer softer wines:

• Grape varieties such as Chardonnay, Viognier (white) or Merlot, Grenache (red)
• Warmer regions (southern France, California, southern Italy)
• Wines that have undergone malolactic fermentation or barrel ageing