Kaliumhydrogenotartrat

Kaliumhydrogenotartrat, also known by its Latin name potassium hydrogen tartrate and commonly referred to as cream of tartar, has the chemical formula KHC₄H₄O₆. It is a white crystalline salt that naturally occurs as a by‑product of the wine-making process. During fermentation, tartaric acid precipitates as potassium hydrogen tartrate on the surface of the wine barrels, and the residue can be dried and processed into the powdered product.

The substance is widely used in both culinary and scientific contexts. In baking, cream of tartar reacts with baking soda to produce carbon dioxide, giving rise to leavening and helping to stabilize whipped egg whites, thus contributing to cake batter lightness and mousse textures. It also serves as an acid in lemonade makers and is used to sharpen the taste of some beverages. In the laboratory, potassium hydrogen tartrate functions as a convenient source of potassium in analytical chemistry and can be used in the synthesis of various inorganic and organic compounds.

Physically, the compound is a hygroscopic white powder with a faint almondish odor. Its melting point is 169 °C, and it decomposes slightly before melting. The salt is considered non‑toxic but may cause irritation to skin and eyes with prolonged exposure. It is commonly available in pharmacy and culinary stores and is labeled as Grade A for laboratory use and as food grade for culinary applications.