NH4HC4H4O6

NH4HC4H4O6 is the chemical formula for ammonium bitartrate, also commonly known as cream of tartar. It is a salt of tartaric acid and ammonia. Structurally, it is composed of ammonium ions (NH4+) and bitartrate ions (HC4H4O6-). Ammonium bitartrate is a white crystalline powder. It is moderately soluble in water.

Historically and in modern applications, ammonium bitartrate is closely related to potassium bitartrate, the more common cream of tartar. Both are byproducts of wine production. During fermentation, tartaric acid and potassium ions react to form potassium bitartrate, which precipitates out as argol. Ammonium bitartrate can also be found in this residue, though in smaller quantities.

In cooking, ammonium bitartrate is primarily used as a leavening agent, often in conjunction with baking soda. When combined, they react to produce carbon dioxide gas, which causes baked goods to rise. It is also used as an emulsifier and stabilizer. In some instances, it can be found in processed foods and confectioneries. Beyond culinary uses, ammonium bitartrate has applications in laboratories as a chemical reagent and in some dyeing processes.