Most baking recipes call for a leavener to give an item airiness and a tender crumb. There are two types: baking soda and baking powder. Why are there two? If I am out of one, can it be replaced with the other? Read further to solve these riddles.
“Baking soda is pure sodium bicarbonate—an alkaline powder (aka, a base). When dissolved in liquid and combined with an acid, it rapidly reacts, breaking down into sodium, water, and carbon dioxide (which) expands upon baking … For baking soda to work, a recipe needs to include a significant acidic ingredient.” So, if you are doing ingredient substitutions in a recipe that lists baking soda as the sole leavener, be sure to keep an acidic item in the ingredient list.
If you are not including an acidic item, then baking powder can work as the leavener. Baking powder is “composed of baking soda, a powdered acid, and a starch (in order to absorb moisture and prevent the acid or base from reacting prematurely) … In its dry state, it’s totally inert. But once you add a liquid, the powdered acid and base dissolve and react with each other, creating bubbles of carbon dioxide without the need for an external acid source.”
There are other actions that baking soda performs and need to be considered. It is also used to “neutralize or dampen acidic ingredients. For this reason it is sometimes used in recipes with a high proportion of ingredients such as lemon juice, buttermilk or other sour flavours. When replacing sugar with a large amount of an acidic sweetener, such as honey, molasses or barley malt syrup, 1/2 teaspoon of baking soda should be added the recipe to account for the increased acidity, even if baking powder is the principle leavener.” Thus, if you are using only baking powder in a recipe with highly acidic ingredients, then the flavor profile may be off due to the extra acid contained in baking powder. Those recipes need a little help from baking soda.
Another interesting baking soda fact is that it increases browning, a reaction that works best in an alkaline environment. Browning not only adds an appealing color to baked goods, but it also enhances the flavor. This is why baking soda is added to some cookie recipes that don’t require the rising action of a leavener.
Because baking soda is so important for many reasons, you may want to keep it on hand instead of baking powder. But, baking powder has its place in baking, too. To simplify things, you can use baking soda to make your own baking powder. “For every teaspoon of baking powder, use 1/4 teaspoon of baking soda, 1/2 teaspoon of cream of tartar, and 1/4 teaspoon of cornstarch.”
Now that we have demystified baking leaveners, you can make substitutions with confidence. It can also help you troubleshoot a quick bread that wasn’t quite perfect. Or maybe that was my recipe that needs some tinkering.