Potassium Hydrogen Tartrate

Cream of tartar is used for a wide variety of applications. It is one of the primary components in baking powder. Here it functions as a leavening agent. Leavening agents are compounds that are put into products like breads and rolls to generate carbon dioxide. The carbon dioxide is trapped in the batter creating air pockets that result in products that are lighter and crispier. In baking powder, cream of tartar specifically functions as the acidic portion that reacts with the basic component, sodium bicarbonate, to generate carbon dioxide gas. The limited solubility of cream of tartar in cold water helps prevent premature leavening. This is useful when mixing dough.

Beyond leavening, cream of tartar also functions as an acidulant in food products. Acidulants serve a variety of purposes in this capacity, but their major role is to make foods more palatable. Acidulants can also be used as flavoring agents because they can intensify certain tastes and mask undesirable aftertastes. They can act as buffers to control the pH during processing. They also have an antimicrobial effect and can prevent the production of spores. They are synergistic with antioxidants which means they help make antioxidants more effective. Acidulants are also viscosity modifiers. By using the appropriate concentration a batter can be made thicker or thinner. They are also melting modifiers and meat curing agents. The addition of cream of tartar to candy and frosting recipes results in a creamier consistency. It can also help improve the stability and volume of egg whites if added before beating.

Non-food applications of potassium hydrogen tartrate include its use as one of the starting materials for the production of tartaric acid. It also finds use in metal processing for such things as coloring and galvanic tinning of metals. In the production of wool it is used as a reducer of CrO₃ in mordants. In the pharmaceutical industry it has been used for its cathartic effect. Veterinarians use it as a laxative and diuretic. Cream of tartar is classified as a generally regarded as safe (GRAS) compound for use in food and beverage products.