Cooks have used cream of tartar for centuries, and snickerdoodles have been around since at least the late 1800s, says food historian Sandy Oliver. But the two don't have to go together. A classic snickerdoodle recipe calls for cream of tartar to give the cookies flavor and texture. But if you don't have cream of tartar on hand, omit this ingredient or substitute another acid.
Cream of tartar is a completely natural by-product of the wine-making industry. Grapes contain tartaric acid salt, a white sediment that remains in the barrels during the wine-making process. This sediment is processed into cream of tartar, a common ingredient in baking powder and often used as a stabilizer in whipped egg whites. In baked goods, it provides leavening and flavor.
A basic snickerdoodle recipe is similar to a sugar cookie recipe. Most recipes call for butter, sugar, eggs, vanilla, flour, cream of tartar and baking powder. In addition to the cinnamon-sugar coating, the main difference between snickerdoodles and sugar cookies is the taste. Cream of tartar imparts a slightly tangy flavor to snickerdoodles. Without this ingredient, the cookies still taste good, but they lack the classic tang.
Another difference between sugar cookies and snickerdoodles is their texture. Sugar cookies tend to be either soft or crispy, which depends in part on how long you cook them. Snickerdoodles are cooked just until the edges brown and the insides are puffy. As they cool, the outsides of the cookies develop their characteristic cinnamon-filled cracks, while the insides have a soft, but chewy, texture. Cream of tartar's leavening power is behind this difference in texture. Without cream of tartar, snickerdoodles aren't as noticeably chewy.
Although you can substitute a teaspoon of lemon juice or vinegar for the cream of tartar, the results aren't quite the same. These substitutes add tang, but they can't duplicate the leavening effects of cream of tartar; the result is a tasty cookie that closely resembles a sugar cookie. Instead, leave out the cream of tartar along with the baking soda if the recipe calls for it. Substitute 1 teaspoon baking powder for each 1/4-teaspoon baking soda and 5/8-teaspoon cream of tartar.