We’re taking science back in the kitchen!
Last blog we discovered how baking soda and baking powder affect our baked goods. If you want to bake some cookies and test it out for yourself, check it out here: Science of Baking Cookies.
Today, we’re going to focus on a different leavening agent: eggs. First, let’s review what we already learned.
Baking soda vs. Baking powder:
Baking soda and baking powder are both leavening agents. Baking soda is usually called for in breads and cakes, while baking powder is more often seen in cookie recipes (although you will see either in all kinds of baked goods). The main difference is that baking soda requires an acid to react, while baking powder does not. Therefore, they are not interchangeable. If your recipe does not have acid, but you use baking soda, you won’t get the desired effects.
Why is this? Baking soda is a base—sodium bicarbonate. In order to react, it needs an acid to react with. Baking powder contains baking soda, but also contains a dry acid. This means it only needs liquid—almost any liquid will do—in order for it to react. When baking soda or baking powder react, the reaction produces carbon dioxide gas. This gas creates bubbles in your baked goods, which helps give them a fluffier texture.
What we found in our last experiment is that using baking soda in a recipe that called for baking powder resulted in flatter cookies. This time, you’ll do a similar comparison with eggs.
Before we move on, what exactly does leavening mean?
Leavening is the process by which dough or batter for breads, cookies, etc. rise or become fluffier. Some breads call for yeast, which takes longer to help the dough rise. Because yeast is actually a living organism, it is a biological leavening agent. Baking soda and baking powder are chemical leavening agents; they help dough rise through a chemical reaction. Another form of leavening is simply through steam. As liquid evaporates, steam rises through the dough, allowing the dough to rise too.
What purpose does an egg serve?
- It adds liquid to your recipe. Thus, leavening through steam can occur.
- When eggs are beaten into other ingredients, air is also incorporated. This also helps baked goods become lighter and more airy.
What’s in an egg?
- Protein
- Fat
- Water
All these nutrients help bind the dough together. Without eggs, many recipes would produce a much drier, crumbly result.
Let’s test this out! You’ll bake two versions of banana bread—one with eggs, and one without.
Here’s the recipe I used:
If you’d like to pick a different recipe, go right ahead! Just make sure that the original recipe calls for eggs.
YOU WILL NEED:
Dry ingredients:
- ¼ Cup Whole Grain Flour
- ¼ Cup White Flour
- ¼ Cup Oats
- 1 Teaspoon Baking Powder
- ½ Teaspoon Baking Soda
- 1 Teaspoon Cinnamon
- 1 Teaspoon Nutmeg
- ½ Teaspoon Turmeric
- ¼ Cup Chocolate Chips
Wet ingredients:
- ½ Cup Almond Milk
- ¼ Cup Coconut Oil
- ¼ Cup Maple Syrup
- 1 Teaspoon Vanilla
- 2 eggs
- 2 mashed bananas
Utensils:
- 2 large mixing bowls for dry ingredients
- 2 medium mixing bowls for wet ingredients
- Muffin tin
- Non-stick spray
- Whisk or large spoon
- Measuring cups and spoons
Here’s what to do!
Mix up two batches of ingredients, one with eggs, and one where the eggs are left out. Make sure you measure each ingredient carefully so your recipes are exactly the same! Bake them at the same time, and make sure to flip the pan halfway through so each batch gets the same baking conditions. That way, you know the only variable in your experiment is the eggs (or lack thereof).
- Pre-heat your oven to 375 degrees.
- Spray your muffin tin with a non-stick spray.
- Mix all your dry ingredients first. Repeat in a second bowl so you have one for each of your two batches.
8. Check back and see how they look so far. What do you notice? Flip the tin around so the muffins get equal baking conditions. I was surprised to see the egg muffins were rising less so far!
With this recipe, the baking soda and baking powder helped both the muffin batches rise about equally. There was, however, a clear difference in appearance. The egg muffins (right) were very uniform. The extra moisture from the eggs probably allowed the batter to settle into the muffin tin and rise more evenly. The non-egg muffins (left) were more misshapen and lumpy, with crunchier tops. The non-egg muffins were very easy to remove from the tin, while the egg muffins took a little extra prying. The egg muffins, when cut in half, were much more moist. They also felt lighter and fluffier. The non-egg muffins were drier and denser.
What did you notice in your recipes?
Extension:
Next, test out the same recipe WITHOUT eggs, baking soda, or baking powder. What kind of results would you expect? Think back to what you’ve learned about the purpose of these ingredients.
Results: The third batch did not rise at all. It was much denser and heavier than either of the first two muffins. It didn’t brown nearly as much (baking soda also has a hand in helping baked goods brown). The surface had a chewier texture, and the center did not bake all the way through in the 40 minutes… it was kind of just mushy in the middle.
Happy baking, and happy muffin tasting!