Baking Powder & Food Science

“In France, cooking is a serious art form and a national sport.”-Julia Child

For several days after a local disaster, odds are you won’t be able to drive to the local grocery store to pick up some missing ingredients. For this reason all preparedness sites will recommend food storage and stocking up on supplies. But sometimes even the best plans have a gap and you discover you forgot something basic like baking powder. When that happens it’s nice to have a list of emergency ingredient substitutions in a good cookbook (like Joy of Cooking) or printed (in advance) off a website like http://chemistry.about.com/od/foodcookingchemistry/a/substitutions.htm?nl=1

What is baking powder and how would you make it? According to Wikipedia, “Baking powder is a dry chemical leavening agent used to increase the volume and lighten the texture of baked goods such as muffins, cakes, and biscuits. … It is used instead of yeast for end products where fermentation flavors would be undesirable or where the batter lacks the elastic structure to hold gas bubbles for more than a few minutes. … Breads made by chemical leavening are called quick breads.”

Baking powder consists of an alkaline/base component (typically baking soda), one or more acid salts and an inert filler (like cornstarch). When the powder (single acting) gets wet the base and acid react producing gassy bubbles. The role of the filler is to extend the shelf life of the powder by absorbing moisture and preventing a reaction in the baking powder container. Over time the filler will be used up and the baking soda goes flat if not tightly sealed.

I used the phrase “single acting” which needs explaining. Baking powder that reacts when wet is single acting. In contrast “double acting” powder requires liquid AND heat to react. Double acting is useful when you want something to rise in the oven while cooking.

If you’re out of baking powder or find that it’s gone flat, you can make it as follows:

1 teaspoon of Single Acting Baking Powder =
1/4 teaspoon baking soda
1/2 teaspoon cream of tartar (an acidic salt)
1/4 teaspoon cornstarch or potato starch

You can leave out the cornstarch if you’re making just enough for one recipe and using it immediately.

Bottom Line

My mother majored in Home Economics at the University of Idaho. One of her textbooks, which I found fascinating as a teen, was called the Chemistry of Cooking. It explained why things happen when you cook. Today a great source for food science facts is the TV show “Good Eats” by Alton Brown on the Food Network. Knowing the science can make one a better cook.

For example, do you know that deep fried food need NOT be greasy! Greasiness is a sign that the oil was not hot enough (perhaps from too much food put in the oil too quickly) or that the food was left in the fryer longer than necessary. Under the right conditions, the food being fried emits steam from the heat of the oil and the steam prevents oil from going into the food.