| an organic compound, C4H6O6, existing in four isomeric forms, the common or dextrorotatory isomer being a white, crystalline, water-soluble powder or transparent crystals: used in effervescent beverages, baking powders, confections, photography, and tanning. |
| tartaric acid n. Any of four isomeric crystalline organic compounds, C4H6O6, used to make cream of tartar and baking powder, as a sequestrant, and in effervescent beverages and photographic chemicals. |
tartaric acid  (tär-tār'ĭk) Pronunciation Key
A crystalline organic acid that exists in four isomeric forms and occurs widely in plants. It is found in byproducts of wine fermentation and has a wide variety of uses, including to make cream of tartar and baking powder, to add effervescence to beverages, to polish metal, in printing and dyeing, and to make photographic chemicals. Chemical formula: C4H6O6. |
tartaric acid
a dicarboxylic acid, one of the most widely distributed of plant acids, with a number of food and industrial uses. Along with several of its salts, cream of tartar (potassium hydrogen tartrate) and Rochelle salt (potassium sodium tartrate), it is obtained from by-products of wine fermentation. In a partially purified form, tartar was known to the ancient Greeks and Romans; the free acid was first isolated in 1769 by Swedish chemist Carl Wilhelm Scheele. The lees, or sediments, and other waste products from fermentation are heated and neutralized with calcium hydroxide; the precipitated calcium tartrate is then treated with sulfuric acid to produce free tartaric acid. Rochelle salt is prepared from the crude crystalline potassium acid salt, called argol, by neutralization with sodium carbonate. Purified cream of tartar comes chiefly from the filtrates from production of the acid and Rochelle salt. A third salt, tartar emetic (antimony potassium tartrate), is made from the potassium acid salt and antimony oxide.
Learn more about tartaric acid with a free trial on Britannica.com.