Did you know that you can substitute white vinegar in place of cream of tartar? It is made from tartaric acid and half neutralized with potassium hydroxide. This process transforms it into a salt. Grapes are the only significant natural source of tartaric acid, and cream of tartar is obtained from sediment produced in the process of making wine. White vinegar or lemon juice, in the ratio of 3 times the amount of cream of tartar called for, will provide the right amount of acid for most recipes. If adding it to egg whites you can sub about 1/8 a teaspoon of white vinegar per egg white. Cream of Tartar stabilizes and adds volume to beaten egg whites and a makes for a creamier texture in sugary desserts such as candy and frosting, because it inhibits the formation of crystals.