E334: L-Tartaric Acid (Wine & Baking Acidulant)

Direct Answer

E334 (L(+)-Tartaric Acid) is a dicarboxylic organic acid recovered as potassium bitartrate by-product from wine barrels. INS 334, ADI has historically been set at up to 20 mg/kg bw/day by JECFA, delivering a sharp, lingering tartness in candies, soft drinks, and baking powders.

Source: EFSA ANS Panel (2020) / Codex · Last reviewed Aug 28, 2026

Specs

E-Number Code	E334
INS / Codex Number	INS 334
Functional Class	Acidity Regulator, Acidulant, Synergist for Antioxidants
Acceptable Daily Intake (ADI)	Historically up to 20 mg / kg body weight per day (JECFA: 0–6 mg/kg unconditional + 6–20 mg/kg conditional acceptance)
Chemical Formula	C4H6O6 (2,3-dihydroxybutanedioic acid)
Primary Mechanism	Stronger sourness profile than citric acid (pKa1 2.98), stimulating salivation and activating baking soda
Common Target Foods	Hard sour candies, baking powder (Cream of tartar), grape beverages, wine adjustment
Dietary Compliance	100% Vegan (Wine by-product), Halal, Kosher
Safety Approval	EFSA Authorized / FDA GRAS (21 CFR 184.1099)

Cream of Tartar in Chemical Leavening

Potassium bitartrate (E336, cream of tartar derived from tartaric acid) is the classic fast-acting dry acid in double-acting baking powders, reacting instantly with sodium bicarbonate on contact with water.