Chemistry and Cupcakes

Baking can teach you a lot of things. Following directions, measuring, fractions, and even chemistry. This is a simple experiment using a basic cake/cupcake recipe that I’ve cut in half for smaller batches. We’ll make eight batches total, and in seven of them we’ll take away an ingredient. You’ll learn how all the ingredients work together to make a delicious cupcake.

Materials:
Sugar, butter, eggs, vanilla extract, all purpose or cake flour, baking powder, milk, cupcake liners, a small cupcake tin, a mixing bowl, an electric mixer, and a spoon.

You’ll also need a notebook and a pencil to record your results.

The first batch will be your control. Having a control in an experiment is important, so you know what happens when everything goes as planned. Because this control turns into tasty cupcakes, you could also double the recipe to make twice as many of the control batch. You know, for science.

For a standard batch of six, take six cupcake liners and write “C” on the bottom (outside) of the liners with pencil before using them to line your cupcake tin.

Basic Cupcakes:
(makes six cupcakes)

½ cup sugar
¼ cup (one half stick) butter
1 large egg
1 teaspoon vanilla
¾ cup flour
1 teaspoon baking powder
¼ cup milk

Using a mixer, cream together the sugar and butter. That means mix them together until they are light, fluffy, and pale. Add the egg and vanilla. Next, mix the flour and baking powder into the batter. Finally add the milk and mix together until blended. Spoon into the paper lined cupcake tin, and bake for 20 minutes at 350 degrees. Allow the cupcakes to cool before eating.

Use your notebook to record the taste, texture, smell, and general appearance of the cupcake. Did it rise? Did it appear to collapse? How is the texture?

For the next batch, write “1” on the bottom of your cupcake liners. This time, follow the same recipe, only leave out the sugar. For batch “2,” you’ll leave out the butter, for batch “3,” you’ll leave out the egg, and so on until you’ve made a batch missing each ingredient. (Make sure you allow extra time for the flourless version to cool–it will be a very hot liquid and might burn if the cupcake tin spills.)

Write down your results for each batch. How was the flavor? Did it rise? Did it collapse? Did the texture change? What role do you think that ingredient serves in the recipe? Would you want to leave it out in the future?

What you witnessed:

Vanilla is the only ingredient in the recipe that doesn’t change the structure of the cake. It only changes the flavor and smell.

The flour forms the main structure for the cake–you may notice that the cake is a pile of goo without it.

Baking powder is a leavening agent that makes a carbon dioxide foam as the batter cooks, and that’s one of the key reasons the cake batter rises. The sugar and butter also help with rising. The fat and sugar are creamed with the mixer, which traps air around the sugar crystals as they’re surrounded by the butter. Those tiny air pockets also fill and expand with the gasses from the baking powder.

The milk and egg proteins act as binders to keep the foam from collapsing as it cools.

The browning and delicious baked smell rely on the Maillard reaction, which is caused by a combination of heat, sugar, and proteins. That’s why the batch with no sugar will also have trouble browning.

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Marziah Karch has written books on topics like Android and LEGO robotics. She is also writes for About.com for money and GlitterSquid for fun. She lives in Portland, Oregon and still works a day job. Because she apparently has free time on top of all that, she is also a doctoral candidate researching the information behavior of independent game designers.