Cookbook:Cream of Tartar

Cream of tartar, also called potassium hydrogen tartrate or mistakenly called tartaric acid, is an ingredient byproduct of wine making.

Characteristics
The substance precipitates out of wine and accumulates in the vats, after which it is harvested and refined into a pure white powder. It is mildly acidic, with an otherwise neutral flavor.

Selection and storage
Cream of tartar should be stored in an airtight container at room temperature. It has a very long shelf life.

Use
Cream of tartar's primary uses come from its acidity. When added to egg whites during whipping, it helps coagulate the proteins and stabilize the foam  —2 tsp per 1 lb whites (20 ml per 1 kg) is recommended. It also often makes up the acidic component of baking powder, and it can help reduce crystallization in sugar syrups, as well as add a neutral sour profile to preparations.