Potassium tartrates

Potassium tartrates — monopotassium tartrate (E336i, known as cream of tartar) and dipotassium tartrate (E336ii) — are the potassium salts of tartaric acid, a by-product of wine production. The most familiar form, cream of tartar, stabilises whipped egg whites by lowering pH, prevents sugar crystallisation in confectionery, acts as the acid component in baking powder, and inhibits tartrate crystal formation in bottled wine.

JECFA's ADI for potassium tartrates is 30 mg per kilogram body weight per day, evaluated in 1978 as part of the group ADI for tartaric acid and its salts. The compounds are metabolised in the gut and partially excreted renally. No adverse effects are known at any realistic dietary exposure, and the potassium contribution from typical culinary or food additive amounts is nutritionally modest for most people.

Potassium tartrates are universally approved in the EU, US (GRAS), UK, Australia, Japan, and Vietnam. Cream of tartar has a centuries-long culinary history and is considered one of the most natural and clean-label baking ingredients available. People on medically restricted potassium diets should monitor intake from cream of tartar when used in large quantities in home baking, but at food additive concentrations in manufactured goods it poses no concern for healthy adults.