Potassium hydrogen tartrate

Potassium bitartrate, also known as potassium hydrogen tartrate, with formula KC₄H₅O₆, is a byproduct of winemaking. In cooking it is known as cream of tartar. It is processed from the potassium acid salt of tartaric acid (a carboxylic acid). The resulting powdery acid can be used in baking or as a cleaning solution (when mixed with an acidic solution such as lemon juice or white vinegar).