Updated April 2022.
Baking powder is used in such small amounts it’s often overlooked in ingredient lists. But this unassuming powder is crucial for volume and tenderness in baked goods such as muffins, biscuits, cookies, and cakes. In this experiment, we varied the amount of baking powder in muffins to see how the muffins would change in appearance, taste, and texture.
Experiment Overview
Goal: To see and taste differences in appearance, taste, and texture in muffins with different amounts of baking powder
Recipe: Best Ever Muffins from AllRecipes
Method: Mix and divide the dry ingredients except for baking powder. Add baking powder as written, twice the amount, or none at all. Add the wet ingredients to each batch of dry ingredients. Bake, cool, and taste.
Results: As baking powder increased, we noticed
– Lighter batter
– Greater volume that subsequently collapsed
– More tender, then chewier texture
– Darker color
– Stronger chemical smell
Conclusions: Leavening is important for volume and tenderness in muffins, but there is a sweet spot. Both under- and overleavened muffins have lower volume and a denser, chewier texture. Baking powder is also important for color.
Testing Method
Ingredients and Equipment
- 2 c (250g) Baker’s Corner bleached all-purpose flour
- 1/2 tsp Stonemill iodized salt
- 3/4 c (150g) Baker’s Corner sugar
- 1 Tbsp Baker’s Corner double-acting baking powder, divided
- 1 c (243 g) Friendly Farms Vitamin D whole milk
- 1 Goldhen large egg
- 1/4 c (60 g) Carlini vegetable oil
- Whisk
- Rubber spatula
- 12-cup muffin pan lined with cupcake liners
Baking the muffins
- Preheat oven to 400°F.
- Whisk the flour, salt, and sugar together in a large bowl (404g total). Divide into three portions (134 g each). To each portion, 1, 2, or 0 tsp baking powder and whisk well. These contain equal (control), double, and none of the baking powder written in the recipe, respectively.
- In a separate bowl, whisk the milk, egg, and vegetable oil together (356g total). Pour one-third (118g) of the wet ingredients into each portion of dry ingredients. Fold the wet and dry ingredients together until just combined.
- Divide each portion of batter into four muffin cups.
- Bake for 21 minutes. Cool on a wire rack for 5 minutes, then remove muffins from pan to cool completely.
Results
To better understand some of these results, I suggest reading through the last few posts about leavening and chemical leaveners, especially the section about baking powder. Remember that baking powder is a mixture of baking soda, acid salts, and a starch filler. The baking powder I used contains the slow-acting acid sodium aluminum sulfate (SAS) and the fast-acting acid monocalcium phosphate (MCP). (For more information on baking powder, check out the post on baking soda and baking powder.)
Lighter batter
The more baking powder the batter contained, the airier it was. This was especially noticeable in the double baking powder batter. Although the muffin batter didn’t have significantly greater volume compared to the control batter, it sounded like an egg white meringue beaten to stiff peaks when I scooped it into the pan.
When we combine the liquid and dry ingredients, water from the milk and egg dissolves the baking soda and the acid salt MCP from the baking powder. Once dissolved, these two chemicals react to produce carbon dioxide gas and some other compounds. (Read more about this process here.) In the double baking powder batter, the extra baking powder added twice as much carbon dioxide gas to the batter and noticeably lightened it.
Greater volume that subsequently collapsed
Once the muffin batter enters the oven, the acid salt SAS from the baking powder dissolves and reacts with the remaining baking soda to produce even more carbon dioxide. As it heats up, the carbon dioxide expands and pushes against the batter around it. (Read more about this process here.) Since the muffins with double the baking powder contained more carbon dioxide gas molecules, it makes sense that they gained volume fastest as the muffins baked. In the image below, which was taken about twelve minutes into baking, the double baking powder muffins are taller, and more batter has flowed over the edge of the pan.
However, while the control muffins developed a nice dome, the tops of the doubled baking powder muffins were flat, as shown below. As the carbon dioxide expands in the oven, it stretches the batter around it thin, like a balloon filling with air. In the double baking powder muffins, the excess gas stretched the batter so much that it weakened the structural molecules in the muffin and they collapsed, forming a flat top. In fact, despite having double the carbon dioxide, the muffins with double the baking powder are similar in size to the control muffins.
On the other hand, the muffins without baking powder did not rise much at all. Since we mixed some air into the batter, they did contain a little gas. And since the batter contained water from milk and eggs, the muffins also had some leavening power from steam. But as you can see from the difference in height, baking powder contributes most of the leavening power in muffins. Without baking powder, the muffin batter doesn’t contain enough gas to expand and rise.
Furthermore, as you can see in the cross sections below, the air pockets inside the muffins without baking powder are few and far between. The tops of the muffins are also wrinkled. In the control muffins, when baking powder starts to release carbon dioxide in the mixing bowl, it enlarges existing air bubbles. These bubbles get broken up into multiple smaller bubbles as we mix the batter. Then, when the batter bakes, expanding carbon dioxide evenly enlarges all of these small bubbles to form a fine crumb and smooth surface. (Read more about this here!) If we remove the baking powder, the muffin batter doesn’t contain enough air bubbles. The few existing bubbles expand unevenly, resulting in irregular holes and an uneven surface.
More tender, then chewier texture
The difference in volume also directly correlated with the muffins’ textures. When carbon dioxide expands in the oven to add volume to the muffin, it also stretches the batter around it like air filling a balloon. The thin, stretched batter results in a tender texture.
As you can imagine from the photo, the muffins without baking powder were chewy, dense, and rubbery. Without carbon dioxide to stretch it, the batter surrounding the air bubbles remained thick, and it baked into a chewy hunk of dough. The texture was reminiscent of mochi, but more rubbery—not what I look for in a muffin. To say the taste testers didn’t enjoy this one is an understatement.
The muffins with twice the baking powder weren’t bad, though when compared to the original recipe, they were noticeably chewier. With double the baking powder, the batter stretched so thin the structure of the muffin collapsed (we saw this in the flat top), and the muffin became denser and chewier. The perfect amount of leavener stretches the batter thin but leaves the structure intact. All three testers preferred the light and fluffy texture of the original muffin recipe to the one with doubled baking powder.
Darker color
As you can see below, the color of the muffins darkened with more baking powder. Browning occurs when sugar caramelizes or reacts with proteins in the Maillard reaction. One factor in the Maillard reaction is pH, or how acidic or basic something is. Acids prevent browning, so the less acidic (or the more basic) the muffin, the darker its color. Since baking powder slightly increases basicity, the more the muffin had, the darker its color.
The Maillard reaction is also influenced by temperature. As all batters and doughs bake, they get hotter, but their temperature is limited by water. As long as liquid water is still evaporating, the batter’s temperature won’t exceed water’s boiling point. Since water doesn’t change its temperature very easily, and there’s usually a lot of it, water typically continues evaporating for the majority of the bake time. Once the water is gone, however, the temperature at the surface of the baked good, which is directly exposed to heat, shoots into ranges where browning reactions occur quickly. The longer the surface is at these high temperatures, the browner it becomes.
The movement of heat through the muffin and the rate of water evaporation depend on many factors, including the amount of air inside the muffin. Since the unleavened muffins contained much less gas than the control muffins, they warmed more slowly, leaving less time for browning. Conversely, the extra leavening gas in the double baking powder muffins helped them heat up and lose water faster. The browning reactions then started earlier, resulting in a darker muffin. All taste testers preferred the darker color of the double baking soda muffins.
Stronger chemical smell
However, the muffins with twice the baking powder had an unpleasant chemical scent that the other two did not. As we discussed, baking powder is a combination of baking soda and acid salts. When they’re dissolved into water, the compounds react to produce carbon dioxide. This reaction also produces a salt. In moderation, this salt contributes a salty-sour taste that adds complexity to the flavor of chemically leavened baked goods. You might taste it in Irish soda bread. However, the more baking powder there is, the more of these salts are left in the muffin. Twice the baking powder gave the muffins an off-putting odor. Any more baking powder and the excess salt would have detracted from the muffin’s taste.
Conclusions
Baking powder is an important ingredient in muffins. It contributes to shape, color, taste, and texture. An ideal muffin uses just the right amount of baking powder: the amount that’s balanced with the other ingredients to create maximum volume, a domed top, good color, and a tender texture. In the next post, we’ll continue exploring the role of chemical leaveners in muffins with baking soda and cream of tartar.
References
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