Bakewell Cream was invented during World War II, when cream of tartar and baking powder were in short supply. The product contains no dairy: The “cream” in its name refers to its use in traditional Maine cream biscuits. It’s actually a mixture of sodium pyrophosphate, a mineral acid, and cornstarch, added to prevent moisture absorption. It can be substituted for cream of tartar or combined in a 2:1 ratio with baking soda as a replacement for baking powder.
We mixed Bakewell Cream with baking soda and used it in our cream biscuit and sugar cookie recipes, finding that it performed just fine as a leavener. As a substitute for cream of tartar, however, it failed to impress: Our cream of tartar meringues were perfectly crisp and bright white, while those containing Bakewell Cream browned before they were fully cooked, leaving their centers gummy. The explanation? It all comes down to pH levels. Browning reactions occur more readily in alkaline environments—such as egg whites. Acidic cream of tartar works rapidly to reduce the pH of egg whites, thereby warding off browning. Sodium pyrophosphate, on the other hand, becomes acidic only when heated in the presence of water. The Bakewell Cream meringues, then, didn’t turn acidic until they were fully heated in the oven, by which time it was too late to prevent them from browning.