Tartaric acid is a white crystalline diprotic acid. This aldaric acid occurs naturally in many plants, particularly grapes, bananas, and tamarinds, is commonly combined with baking soda to function as a leavening agent in recipes, and is one of the main acids found in wine. It is also added to other foods to give a sour taste, and is used as an antioxidant. Salts of Tartaric acid are known as Tartrates. It is a dihydroxyl derivative of Succinic acid.

Tartaric acid was first isolated from Potassium tartrate, known to the ancients as Tartar. Tartaric acid played an important role in the discovery of chemical chirality. This property of Tartaric acid was first observed in 1832 by Jean Baptiste Biot, who observed its ability to rotate polarized light. Louis Pasteur continued this research in 1847 by investigating the shapes of ammonium sodium tartrate crystals, which he found to be chiral. By manually sorting the differently shaped crystals under magnification, Pasteur was the first to produce a pure sample of levo-tartaric acid.

Tartaric acid and its derivatives have a plethora of uses in the field of pharmaceuticals. For example, Tartaric acid has been used in the production of effervescent salts, in combination with citric acid, in order to improve the taste of oral medications. The potassium antimonyl derivative of the acid known as Tartar emetic is included, in small doses, in cough syrup as an expectorant.

Tartaric acid also has several applications for industrial use. The acid has been observed to chelate metal ions such as calcium and magnesium. Therefore, the acid has served in the farming and metal industries as a chelating agent for complexing micronutrients in soil fertilizer and for cleaning metal surfaces consisting of aluminium, copper, iron, and alloys of these metals, respectively.