Cream of Tartar is used as a home and kitchen remedy to help treat high blood pressure, urinary tract infection, sore throat and arthritis. Cream of Tartar (Potassium bitartrate, Potassium hydrogen tartrate) is an acidic salt that is most commonly used for baking and cooking purposes. Cream of tartar is best known for helping stabilize and give more volume to beaten egg whites. It is an ingredient in some brands of baking powder.