Tartaric vs Citric vs Malic Acid: Which to Add to Your Wine and When

Acid adjustment is one of winemaking’s most impactful interventions. The type of acid you add—tartaric, citric, or malic—matters as much as the amount. Here is when and how to use each.

Why Acid Balance Matters

Proper acidity affects everything:

• Microbial stability: Lower pH inhibits spoilage organisms
• Color stability: Acids help fix anthocyanins (red pigments)
• Flavor balance: Acid provides lift and brightness
• Aging potential: Proper acid structure supports longevity
• Sulfite effectiveness: SO2 works better at lower pH

Target pH for most wines is 3.2-3.6, with titratable acidity (TA) of 6-9 g/L.

Tartaric Acid: The Gold Standard

Tartaric acid is naturally dominant in grapes and the preferred acid for wine adjustments. It is stable, does not ferment, and integrates well.

When to use: Most acid adjustments, especially before fermentation. Safe choice when you are unsure.

Characteristics:

• Tastes crisp and clean
• Stable during fermentation
• May precipitate as tartrate crystals in cold weather
• Most natural-tasting addition

Dosage: 1 g/L raises TA by roughly 1 g/L and lowers pH by 0.1 (varies by buffer capacity)

Citric Acid: Use With Caution

Citric acid provides bright, lemony acidity but comes with significant caveats.

When to use: Only after fermentation is complete and malolactic fermentation is finished. Citric acid is metabolized by lactic acid bacteria, producing diacetyl (buttery) and potentially volatile acidity.

Characteristics:

• Tastes sharper than tartaric
• Can be metabolized by bacteria
• May create off-flavors if MLF is not complete
• Good for small adjustments near bottling

Limit: Do not exceed 0.5 g/L in finished wine

Malic Acid: The Freshness Factor

Malic acid is the “green apple” acid. It provides fresh, vibrant acidity but is consumed during malolactic fermentation.

When to use: Only if you are NOT conducting MLF, as lactic acid bacteria convert malic to lactic acid. Adding malic to a wine that will undergo MLF is pointless.

Characteristics:

• Sharp, green apple character
• Consumed by MLF bacteria
• Works well for white wines without MLF
• Can taste harsh if over-used

When to Add Acid

Before fermentation: Best time for significant adjustments. Yeast work better at appropriate pH, and acid integrates during fermentation.

After fermentation: Fine-tuning adjustments only. Large additions post-fermentation taste more artificial.

At bottling: Very small adjustments if absolutely necessary. Use citric acid cautiously.

Testing Before Adjusting

Always measure pH and TA before adding acid. Calculate the adjustment needed. Then add in increments, testing after each addition. It is easier to add more acid than to remove it.

Reducing Acidity

If wine is too acidic, options include:

• Potassium bicarbonate: Chemically neutralizes acid
• Cold stabilization: Precipitates tartaric acid as crystals
• Malolactic fermentation: Converts harsh malic to softer lactic
• Blending: Mix with lower-acid wine