Cocoa powder is an unsweetened powder produced by grinding cacao beans and pressing out the cocoa butter, better known as fat. The resulting cocoa powder is low in fat, but has an intense chocolate taste. It is most commonly used in baked goods, where it is mixed with sugar and fats, such as butter, margarine, or coconut oil. While sugar can add to your waistline, it is not considered a fat.
Difference Between Alkalized and Natural Cocoa Powder
Cocoa powder is commonly available in two varieties: natural cocoa powder, and alkalized, or "Dutch-processed," cocoa powder. Dutch-processing cocoa powder involves treating the cocoa with an alkali to reduce the acidity, and thus, remove sour flavors. Dutch-processed cocoa often has a deeper or redder brown color, and a more palatable flavor, because some of the acidity has been removed. Still remaining is that rich chocolatey taste. For home baking, you usually use more sugar in the processed variety of cocoa powder.
For candy making, the types of cocoa powder can usually be used interchangeably, and you should use whichever cocoa you think tastes best. For baking, the type of cocoa can matter, because the acidity of the cocoa powder can react with whatever leavening agent the recipe calls for. If the recipe calls for baking soda, for example, natural cocoa powder is preferred, because the acidity in the cocoa will react well with the baking soda. If the recipe calls for baking powder, then Dutch-processed cocoa powder should be your preference.
Cocoa Powder as a Baking Chocolate Substitute
If you have a recipe that calls for melted unsweetened chocolate, it's easy to use cocoa powder as a substitute. For every 1 ounce of unsweetened chocolate called for in the recipe, replace it with 3 level tablespoons of unsweetened chocolate plus 1 tablespoon of fat—melted butter, margarine, or oil.
Substituting melted unsweetened chocolate for cocoa powder is a much harder task, and isn't recommended, as the percentage of fat and cocoa solids are difficult to replicate in a simple formula. If you want to try, Serious Eats provides this conversion recommendation:
Weight of Unsweetened Chocolate x 5/8 = amount of needed cocoa powder
Weight of Unsweetened Chocolate x 3/8 = amount of needed additional fat
In other words, if a recipe calls for 200 grams of unsweetened chocolate, multiply that quantity by 5/8, which equals 125. To determine the amount of additional fat needed, multiply 200 times 3/8 to get 75. Therefore, the adjusted recipe would use 125 grams of cocoa powder and 75 grams of fat. Since most people don't have pure cocoa butter in the cupboards, your best alternative is shortening, which is low in moisture, bland like cocoa butter, and melts in a similar way.
When Do I Use Cocoa Powder in Candy Making?
Cocoa powder is frequently used in fudge, but can also be a coating on chocolate truffles. It's also used in other candy recipes, such as Cocoa Mints, Chocolate Marshmallows, and Tiramisu Truffle Squares. One of the advantages of cocoa powder is its shelf life; it stores well in glass jars.