Calcium tartrate

Calcium tartrate is the calcium salt of tartaric acid, occurring naturally in grape must and wine as a sparingly soluble precipitate known as "wine diamonds" or "wine stones." As a food additive it functions as an acidity regulator and stabiliser in confectionery, wine, and bakery products. It is often recovered from wine production as a by-product and repurified for food additive use, giving it one of the more naturally derived profiles among acidity regulators.

JECFA's ADI for calcium tartrate is 30 mg per kilogram body weight per day, evaluated in 1978 under the group ADI for tartaric acid and its salts. It is metabolised to tartaric acid and calcium through intestinal bacterial fermentation and renal excretion. No adverse effects have been identified at any realistic dietary intake.

Calcium tartrate is approved in the EU and most global markets. It is encountered in wine, confectionery, and cream of tartar preparations. The calcium contribution is nutritionally neutral at typical use levels. For the general population there are no safety concerns. Consumers with a history of calcium oxalate kidney stones should discuss tartaric acid intake from all sources with their healthcare provider, though evidence for a clinically meaningful effect at food additive doses is limited.