Listen to Dr. Lisa Chirlian show Kathy the science behind muffins!
- follow along with the steps below!

This is a project, because you can eat the results, but we are going to design the project keeping scientific principles in mind

What makes a tender muffin? When you cut open a muffin you will see lots of small holes inside. These holes make muffins tender—not crisp like a cracker or chewy like a bagel—and are formed by carbon dioxide bubbles that occur in the batter. What makes these bubbles? They are formed by the quick chemical reactions of baking powder or baking soda (leavening agents) and liquids, heat and other ingredients in the recipe. In a tender muffin, the bubbles have moved quickly through the batter leaving a network of small holes behind.

Recipes for quick breads almost always emphasize gentle mixing of the batter. “Lumps are ok!” the instructions say—even though they may look bad. Why do they say this? It’s because over mixing the batter will create conditions that lead to rubbery muffins and nobody wants that!

What happens when the batter is over mixed? Changes occur in the flour—specifically to protein molecules. When flour is mixed with water, these proteins link together forming gluten. Gluten is a stretchy network of protein molecules that gives yeast breads (like bagels) their chewy texture. Since we want to make tender muffins, we want to minimize gluten formation.

To minimize gluten formation, minimize mixing flour and liquid! To do this quick breads are made using two bowls. All the dry ingredients (flour, sugar baking powder, etc.) go in one bowl and all the liquid ingredients (oil, eggs, milk, etc.) go in another. Each bowl can be stirred together without any gluten formation. The secret to tender muffins is quickly and gently mixing (folding) the wet and dry ingredients together.

You can test this idea using your favorite muffin recipe. Make the batter in the usual two bowl way, folding the dry ingredients into the wet, leaving some lumps. Pour the batter into half of the muffin cups. Next, over mix the batter. Using a portable mixer will make this easy. Notice how the texture of the batter changes. Pour the over mixed batter into the remaining muffin cups and put them in the over. Be sure to observe the muffins cooking every few minutes because gluten formation will also affect how the muffins rise.

Materials:

Basic muffin recipe (12 muffins)
Electric hand mixer/wooden spoon
Muffin tin

Procedure:

1) Make the muffin batter according to the recipe. Don’t over mix. Fill six of the muffin cups 2/3 full (or as specified by the recipe).

2) Use the electric hand mixer or wooden spoon to beat the better thoroughly. Observe how the texture and appearance of the batter changes. Fill the remaining muffin tins.

3) Cook the muffins according the recipe instructions. Observe (through the oven window) how each set of muffins rises. What do you notice?