Cream of tartar is a common baking additive. It is an acid salt called potassium hydrogen tartrate and made from the sediment left behind in the process of making wine. Cream of tartar is most widely used to stabilize and add volume to egg whites. It is also used to keep sugary desserts from turning grainy or crystallizing. There are apparently no known side effects to consuming cream of tartar.
Cream of tartar is known chemically as potassium bitartrate, or tartaric acid. It is a white crystalline powder which is soluble in water and alcohol. It is created naturally when wine ferments, and is used as an anti-oxidant in food. Cream of tartar is biodegradable, and has no known pollution problems associated with it. It is used mainly as a flavor enhancer, but it is also used in some ceramics, textile processing, mirror silvering and metal coloring.
In the Kitchen
Most acids found in the kitchen, such as apple cider vinegar, are in liquid form. Having a dry acid such as cream of tartar is very useful for some purposes. It gives a creamy texture to candy and frosting. It increases the volume of beaten egg whites. Mixed with baking soda, it becomes double-acting baking powder and can be used as a leavening agent in quick breads and cakes. It can reduce the discoloration in boiled vegetables.
There are a couple of home remedies using cream of tartar, but none have been clinically proven as being effective. The juice of a lemon plus 2 tsp. cream of tartar stirred into a 1/2 cup water and taken once a day for three days is reported to safely lower blood pressure, especially in pregnant women. Drinking a glass of water with 1 tbsp. cream of tartar stirred in it is an old home remedy for improving urinary tract infections. Consult a qualified health care professional before attempting any form of self-treatment.