noun From Latin acidus (sour), from acere (to be sour)

Acidity /əˈsɪdɪti/

The collective term for the natural acids present in wine — primarily tartaric, malic and lactic. Acidity creates freshness, sharpness and a mouthwatering sensation on the palate, and is essential for balance, food pairing and the ability to age.

The main acids in wine

Tartaric acid Grape berry

The most abundant acid in ripe grapes. Stable during fermentation. Contributes a crisp, clean sharpness.

Malic acid Grape berry (especially unripe)

Green-apple character. Reduced during ripening; in cooler climates higher levels remain. Converted to softer lactic acid during malolactic fermentation.

Lactic acid Produced during malolactic fermentation

Softer, milkier character than malic. Most red wines and many Chardonnays undergo MLF to convert sharp malic acid to lactic.

Citric acid Grapes (small amounts)

Minor acid in wine; more common in winemaking additions for freshness.

How to taste acidity

Acidity is felt primarily at the sides of the tongue and on the inner cheeks — it produces a mouthwatering, saliva-stimulating sensation. To isolate acidity, swallow or spit the wine and notice whether your mouth salivates. High acidity triggers a pronounced response; low acidity leaves your mouth feeling flatter. In formal tasting, acidity is described as low, medium(-) medium, medium(+) or high. The How to taste wine guide covers this and the other four structural components systematically.

Acidity and food pairing

High acidity is one of the most useful qualities in a food wine. Acid cuts through fat and richness — this is why Chablis with oysters or Sancerre with goat's cheese work so well. The wine's acidity cleanses the palate between bites. Conversely, acidic foods (tomatoes, citrus, vinegar-dressed salad) can make low-acid wines taste flat; matching with a high-acid wine restores the balance. Use the food pairing tool to explore how acidity level interacts with different food types.

Sparkling wines depend on acidity structurally — the bubbles amplify sharpness, and the sugar added at dosage partially counterbalances it. Very low-acid base wines make poor sparkling wine; this is why Champagne's chalk soils — which produce naturally high-acid grapes — are so valued. See the Champagne dosage rule change for how residual sugar interacts with perceived acidity in finished Champagne.

How to describe acidity in wine and understanding wine pH

Wine acidity is one of the five structural components assessed in systematic wine tasting. How to describe acidity in wine follows a standardised scale: low (the wine feels soft, broad, almost flat), medium (balanced, refreshing but not sharp) and high (the wine stimulates pronounced salivation, feels crisp, sharp and lively). Acidity interacts with other structural elements — high acidity can make residual sugar less perceptible (which is why off-dry Riesling does not taste sweet), and can make tannin feel more aggressive. Wine pH is the measurable counterpart to perceived acidity: most wines fall between pH 2.9 (very high acid — Mosel Riesling, Champagne base wines) and pH 3.8 (lower acid — warm-climate Grenache, ripe Merlot). A lower pH number means higher acidity. Winemakers track both pH and titratable acidity (TA, measured in g/L) because each tells a slightly different story — pH predicts how the wine will taste and how stable it will be, while TA measures the total concentration of acid present. WSET tasting curricula and GuildSomm resources both cover acidity assessment and wine pH in detail.

Sources: WSET (tasting and viticulture curricula), OIV (oenological definitions and acid measurement standards), AWRI (wine acidity and tartaric acid chemistry research). Last updated: 2026-10-14. Corrections via the contact form.

Questions

About acidity.

What does acidity feel like in wine?

Acidity creates a mouth-watering, salivary response — the puckering sharpness you feel at the sides of your tongue and cheeks. High-acid wines stimulate saliva production, which makes them feel fresh and food-friendly. Very high acidity without enough fruit or sweetness to balance it can feel harsh or tart. Low acidity produces a flat, flabby, less refreshing sensation. Acidity is one of the five structural components assessed in formal wine tasting — alongside sweetness, tannin, alcohol and body. See the How to taste wine guide for how to evaluate each systematically.

How does climate affect wine acidity?

Cool climates produce higher-acid wines because grapes ripen slowly and retain more natural malic acid. Warm climates metabolise acids during ripening, producing lower-acid, riper-tasting wines. This is why Chablis (cool northern Burgundy, chalk soils) has noticeably sharper acidity than a warm-climate Australian Chardonnay from the same grape variety. The Cool and warm climate styles guide explains this relationship in detail.

What is malolactic fermentation and how does it affect acidity?

Malolactic fermentation (MLF) is a bacterial conversion of sharp malic acid into softer lactic acid. It is standard practice for almost all red wines and for Chardonnay intended to have a rounder, fuller style. Wines that skip MLF — Sauvignon Blanc, Riesling, Vinho Verde, most Pinot Grigio — retain higher acidity and a crisper profile. Winemakers control whether MLF occurs by temperature management and sulphur dioxide additions. For more on the winemaking steps that affect acidity, see the Red, white, rosé and sparkling methods guide.

Why is acidity important for sparkling wine?

Sparkling wine base wines need high acidity because the bubbles amplify any tartness on the palate and the sweetness added at dosage (in traditional method) partially balances it. Champagne's chalk soils and cool climate produce naturally high-acid Chardonnay and Pinot Noir — perfect for sparkling base wine. This is precisely why English and Welsh sparkling wines have succeeded: the same chalk geology as Champagne, producing similarly high-acid base wines. See the English sparkling wine record exports for context.

What is the pH of wine and how does it relate to acidity?

Wine pH typically ranges from 2.9 to 4.0. Lower pH means higher acidity (more acidic). Most table wines fall between pH 3.0 and 3.8: high-acid whites like Mosel Riesling and Chablis sit around pH 2.9–3.2; full-bodied reds like Merlot and Grenache around pH 3.5–3.8. Winemakers monitor pH (alongside titratable acidity, measured in g/L) during winemaking because pH affects microbial stability, the effectiveness of sulphur dioxide, and how the wine tastes. A wine can have moderate total acidity but feel crisper if its pH is low — which is why pH is as important as the simple g/L acid number.

How do you describe acidity in wine tasting notes?

In a tasting note, acidity is described using a standardised scale (low, medium-minus, medium, medium-plus, high) and by its character. Low acidity: the wine feels soft, broad and lacking freshness — common in warm-climate reds like ripe Grenache or Merlot from hot vintages. Medium acidity: balanced, pleasant freshness without sharpness — typical of mid-weight wines like Chianti, Côtes du Rhône or New Zealand Chardonnay. High acidity: pronounced mouth-watering, salivating sensation that makes the palate feel alive — Mosel Riesling, Chablis, Champagne, Vinho Verde. Wine pH gives a measurable reference: wines below pH 3.2 are high-acid; wines above pH 3.6 are low-acid. Beyond the scale, descriptors like "crisp," "tart," "racy," "zesty" and "refreshing" indicate high acidity, while "soft," "round," "flabby" and "flat" suggest low acidity. See the how to taste wine guide for the full systematic approach to assessing acidity alongside the other four structural components.

Does acidity help wine age?

Yes — high acidity is one of the key structural components that allows wine to age well. Acids act as natural preservatives, maintaining freshness and preventing premature oxidation. High-acid white wines (Riesling, Chablis, Chenin Blanc) can age for decades — their acidity evolves from sharp to honeyed and complex over time. Low-acid wines age less gracefully, tending to flatten and lose freshness. In red wines, acidity works alongside tannin to create the structural backbone for ageing.