Cream of tartar may seem like an enigma, and for good reason—it's not even a cream, nor is it related to tartar sauce. So what is it? Also known as potassium bitartrate, it's an acidic salt that is a byproduct of winemaking. It's used primarily in cooking and baking, but when combined with other ingredients, it has other handy uses around the house, too.
Cream of tartar helps stabilize egg whites, making them fluffier and better able to retain air and hold their shape when baked. It can also keep egg whites looking extra bright and white. Cream of tartar is most often used when making meringue, angel food cake and soufflé. Add 1/8 teaspoon cream of tartar per egg.
If you want smooth, creamy-looking icing or candies, cream of tartar can help. Add a pinch to cooked sugar to prevent the sugar from sticking to itself and forming crystals, which can make the finished product look rough. These are some sweets that get their smoothness in part from cream of tartar:
Baking Powder Substitute
When you're out of baking powder, add two parts cream of tartar to one part each of cornstarch and baking soda. Dissolving cream of tartar in water triggers the baking soda and helps make baked goods rise naturally in the oven.
Cream of tartar is pretty useful outside of the kitchen, too. To remove stubborn laundry stains, pretreat with a paste of lemon juice and cream of tartar. A paste of water and cream of tartar can help rejuvenate scratched dishes and clean aluminum pots and pans. A mix of hydrogen peroxide and cream of tartar can remove stains from tubs, sinks and toilet bowls.