Cream of Tartar

Also known as potassium acid tartrate, this by-product of the wine industry has an indefinite shelf life. Use 1 teaspoon cream of tartar per 1 cup egg whites (⅛ teaspoon per egg white), and it stabilizes the egg whites so that it becomes impossible to dry them out by overbeating. Cream of tartar is also an effective interfering agent in sugar syrups for making caramel, to inhibit crystallization. I also add a little to the water when baking a cake in a water bath; it keeps the aluminum pans from discoloring.