baking powder, baking soda, culinary lesson
Culinary Lesson #2 - Baking Soda vs. Baking PowderTuesday, April 10, 2012
A4: As most of you are aware, both of these white powders are chemical leaveners that are commonly used when making brownies, cookies, or quick breads. When properly combined with an acid, these leaveners create carbon dioxide, which creates air pockets and causes baked goods to rise. But why have two different products that do the same thing? Without getting into too much detail on the chemical differences between the two, I'll tell you that a great place to start is by looking at the ingredients listed on each product.
With baking soda, you'll notice that there's only one ingredient: sodium bicarbonate (NaHCO3). With baking powder, though, you'll see that baking soda is actually a main ingredient, followed by cream of tartar and cornstarch. So what's going on?
To start off, note that cream of tartar is an acidic powder, while cornstarch is a thickening agent that is great at absorbing water. This leads us to believe that since baking powder already consists of an acid, all it needs to start its reaction is a little bit of water. And as an added precaution to prevent this reaction from occurring prematurely, cornstarch is typically added to absorb any moisture in the container. Baking soda, on the other hand, must need some additional acid added to a recipe to create the proper reaction.
You can test this out by pouring some water over separate piles of baking soda and baking powder. Baking soda should show little to no reaction, while the baking powder will bubble away.
So the next time you use a recipe that uses just baking soda as a leavening agent, you'll know that one of the other ingredients listed has the acidic properties needed to form a reaction. Similarly, the next time you use a recipe that calls for just baking powder as a leavening agent, water is the only ingredient needed to start the reaction. Now what about recipes that call for both? Those just mean that a precise amount of baking soda was needed to neutralize a certain acidic ingredient, but more of a reaction was needed to create the 'desired lift'. To create this lift without the unpleasant taste of baking soda that has not been neutralized, baking powder was also used.
Alas, mystery solved!