News-Letter

Media Credit: Britni Crocker The next time you bite into a delectable cupcake, take a minute to appreciate the chemistry involved.

You've cleared away a spot on the kitchen counter and scrounged together bowls, spoons and a measuring cup. (You don't really need a mixer, right?) You're totally prepared to try that great new recipe from the News-Letter.

Too late, you realize you are out of eggs and the baking soda is spilled inside the fridge, missing everything except taco shells and ketchup. Your roommate passes by, shaking salt into his Easy-Mac, appearing perplexed. The shaker is empty.

Have your baking dreams already been whisked away? Not if you understand how your ingredients work. And that's all science.

The most important ingredient in baking is the leavening agent. A typical leavener uses a chemical reaction between an acid and a base that causes the batter to rise. In a recipe, this is usually baking powder or baking soda. What is the difference?

Baking soda, or sodium bicarbonate, is simply a base. It is used to neutralize other acidic ingredients, such as vinegar, brown sugar or honey. Baking soda releases bubbles of carbon dioxide when mixed into the moist batter. These bubbles cause the batter to rise.

Baking powder, on the other hand, is a dry mixture containing baking soda, some acid salts and cornstarch. The baking soda reacts with the acid salts in the powder, in addition to any other acidic ingredients, only when the mixture is moistened. To prevent the reaction from occuring before it is added, baking powder includes cornstarch as a drying agent.

Hold on - baking powder already contains baking soda? Then why would a recipe call for both ingredients?

In this case, baking powder is doing most of the leavening of the batter, while the baking soda is present to neutralize the rest of the acids. By itself, baking soda produces the strong base sodium carbonate along with carbon dioxide, which causes the entire mixture to be slightly too basic and can result in a stomachache for whoever eats the baked goods.

Even though baking soda is about four times as strong as baking powder, the production of this extra base means it is less efficient at making carbon dioxide and therefore at leavening the batter.

Double-acting baking powder reacts in two stages - when moistened and when heated. This lets the batter start to react when mixed in the bowl and to rise further while baking in the oven. Most powder on the shelves today is double-acting.

Continued...

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