Make Homemade Baking Powder and Why You Should Try It

Why would you ever want to make your own baking powder when it’s readily available and inexpensive at the store? There are several good reasons. You might run out unexpectedly, prefer to avoid certain additives, or want a fresher, cleaner-tasting leavening agent for home baking.

One common situation is simply running out. I once returned from shopping without baking powder and had to improvise. I don’t keep self-raising flour in the pantry, so not having baking powder made a simple Sunday-night baking task more complicated. Rather than send my husband on a late-night grocery run, I mixed up my own baking powder in minutes.

Most kitchens already have the two basic ingredients: bicarbonate of soda (baking soda) and cream of tartar. I keep bicarbonate of soda on hand for cleaning and cream of tartar for occasional recipes, such as homemade playdough. Those two items are enough to make effective homemade baking powder.

Another reason to make it yourself is to avoid added aluminium found in some commercial baking powders. Many brands include aluminium compounds, such as aluminium sulphate, which act as heat-activated acids. The difference between homemade and some commercial formulations is how and when the gas is produced. Bicarbonate of soda and cream of tartar react as soon as they meet liquid, producing carbon dioxide and beginning the leavening process immediately. That works well if you bake right away, but if batter sits on the counter for an hour or more before going into the oven, it can lose its lift.

Manufacturers add aluminium-based acids so part of the reaction waits until the mixture is heated in the oven. That provides a safety net if batter sits too long before baking. Be aware that self-raising flour products can also contain aluminium-based ingredients, so avoiding packaged baking powder doesn’t automatically mean you avoid aluminium if you use self-raising mixes.

Many people report that homemade baking powder, which contains no aluminium, avoids a faint metallic aftertaste sometimes noticed with store-bought varieties. I haven’t run a formal test, but in my experience the muffins I made with fresh homemade baking powder tasted better—lighter and more pleasant. Typically my muffins turn out dense or dry, but this batch was noticeably light and fluffy, which I attribute to the freshness of the leavening.

Commercial baking powders also include fillers such as wheat flour (contains gluten), rice flour (gluten-free) or corn flour (which may be GMO). Fillers help prevent clumping and protect the mixture from humidity during storage. If you make a big batch to store, you can add a small amount of rice or corn flour to reduce clumping. For best performance and pure results, though, prepare smaller batches without fillers so the leavening stays fresh and potent.

Whether homemade or store-bought, baking powder can lose potency over time. To test if yours is still active, place 1/2 teaspoon in a small bowl and pour about 1/4 cup of boiling water over it. If the mixture bubbles vigorously right away, it is still good to use.