Tartaric acid

Tartaric acid (CAS 87-69-4), also known by its food additive designation E334, is a naturally derived organic acid sourced primarily from wine production byproducts.

Where is Tartaric acid used?

• Food and beverage: acidulant, pH regulator and antioxidant stabilizer; sharpens tartness in confectionery, soft drinks and baking powders
• Pharmaceuticals: buffering agent and excipient in effervescent tablets
• Personal care: pH adjuster in creams, serums and exfoliating products
• Winemaking: corrects acidity in must and finished wine
• In baking powders its interaction with sodium bicarbonate drives leavening performance.
• Used in medicine for the production of active ingredient salts.
• Serves as a preservative and helps set gels in food products.
• In chemical peeling solutions combined with citric acid and malic acid, it is claimed to remove dead skin cells effectively.
• Salts (tartrates) form complexes with metals by binding many metal ions strongly.

Good to know: Food-grade material conforming to FCC, E334 and BP/Ph. Eur. specifications is the most commonly traded form; technical-grade material is also available for non-consumable industrial applications.

Formulation notes

• For must or grapes, the legal maximum use dose is 150 g/hL.
• L(+) tartaric acid (natural) should not be confused with synthetic tartaric acid made from maleic acid.
• Less aggressive than vinegar or citric acid but still has a mildly corrosive effect.

Typical specification

• pKa values of 2.98 and 4.34, making it a medium-strong to weak acid.
• Supplied in crystal and powder forms, white in color.
• Melting point of 170 °C for the L- and D-forms.

Regulatory status

• Acidification with tartaric acid is only authorized in certain wine-growing zones of the European Union.
• Authorized in most food products and in specific products such as cocoa and chocolate products, jams and jellies, and canned fruits and vegetables.

Storage, packaging and handling

• Should not be stored in areas directly exposed to sunlight because it converts to glyoxylic acid.

Frequently asked questions about Tartaric acid

Does tartaric acid react with silver?

Yes, tartaric acid reacts with silver nitrate to give mirrors a silver color.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.