Can You Really Use Baking Powder To Thicken Sauces?

Baking powder is a mixture of baking soda and cream of tartar. It works as a leavening agent in baking because the baking soda and cream of tartar create a "bubbling" reaction that can give your baked goods a "rise." Although baking powder contains baking soda, it's not necessarily a good substitute for baking soda in baked goods because the cream of tartar can imbue the finished product with unwanted flavor notes, according to Sally's Baking Addiction. In addition, some baking powder is formulated with cornstarch as a stabilizer (via Web Restaurants Store). While cornstarch has qualities that make it useful in some baking recipes, including desserts that are meant to be light and chewy, according to Bob's Red Mill, those qualities may not be desirable in others. 

On the other hand, if your baking powder contains cornstarch, it may have a superpower you never realized: You may be able to swap it for wheat flour and other gluten-containing starches when thickening savory sauces (as well as soups, stews, and stocks), according to Modern Mom.

When baking powder contains cornstarch, you may be able to use it as a thickener for sauces, according to Modern Mom, which explained that cornstarch "binds the wet ingredients together for a smoother and thicker substance." That being said, Modern Mom cautions against using "too much" baking powder as a thickener because it can leave your finished product tasting "bitter or salty." Our Everyday Life explained that this is because "the acid salts and the baking soda produce a gas when heated or added to liquids," such that "the resulting sauce may bubble and have a bitter taste." In addition, too much of any thickener can lead to an overly thickened finished product.

To use baking powder to thicken a hot liquid, rather than whisking it in directly, it's advisable to spoon some of the liquid into a separate container and whisk the baking powder into that to create a "slurry." After you've whisked out any lumps from the slurry, add it slowly into your hot liquid. If you find the liquid hasn't thickened enough, you can add a bit more slurry, albeit slowly to make sure you're preserving the desired taste and consistency of your finished product. Additionally, Our Everyday Life pointed out that because cornstarch loses its potency as a thickener when mixed with acids, it's best not to substitute baking powder for other starches for thickening sauces that contain "acidic ingredients" such as lemon or tomato.