You might have noticed that some recipes call for unsweetened regular, or “natural,” cocoa powder while others call for Dutch-processed cocoa. Regular cocoa is intense and full flavored; it’s also somewhat acidic. Dutch-processed cocoa (also called Dutched or European-style) is treated with an alkali to neutralize its acidity. The treatment process, invented by a Dutchman in 1828, smoothes and mellows the cocoa’s flavor and darkens its color.
The two types of cocoa aren’t necessarily interchangeable because the leavening agents in recipes are typically balanced against the specific pH of the cocoa. (That is, baking soda, which is alkaline, is generally paired with natural cocoa to neutralize its acidity; baking powder is paired with Dutched cocoa because both ingredients are essentially neutral already.) A well-stocked baker’s pantry includes both types. Dutch-processed cocoa isn’t as widely available as natural cocoa, but some supermarkets do carry both. Chocosphere.com carries a wide selection of cocoa powder.