The Best Way To Prevent Muffins From Deflating
There's nothing worse than taking your muffins out of the oven only to find out they've fallen flat or sunken in. It's a common mishap when baking muffins, but fortunately one that has an easy fix. According to Handle the Heat, the solution is simply to chill the muffin batter beforehand. While you might be tempted to put them in the oven right after mixing together a batch, muffins baked at room temperature don't rise as well.
This applies to all muffin recipes, so if your muffins aren't getting a high enough rise, the good news is you won't have to switch to a new recipe. You may, however, have to switch to double-acting baking powder if you're using the aluminum-free kind. As Epicurious explains, aluminum-free baking powder activates with liquid (and quickly), which means the longer it sits in the refrigerator, the more it'll lose its effectiveness. Double-acting baking powder, on the other hand, is activated twice — first by liquid, then by heat — so your muffins will rise in the oven, too, giving them plenty of time to chill in the refrigerator.
What does chilling your muffin batter before baking do?
When it comes to baking, sometimes the waiting period is the most important part. Refrigerating cookie dough allows the flavors to intensify, tres leches cake requires soaking overnight, and you wouldn't bake bread unless you proofed it first. As for muffins, chilling the batter before baking allows gluten to develop. Kitchn explains that gluten development is crucial in muffins because it's what gives it its classic domed shape. Without enough gluten, muffins don't have enough structure, so while the baking powder will cause the tops to rise, they'll eventually deflate when it's time to take them out of the oven, because there's not enough gluten to support it.
By chilling muffin batter in the refrigerator, you're essentially giving the flour more time to absorb the liquid ingredients, and in doing so the starches swell and allow more gluten to form. This in turn improves the consistency of your batter, letting your muffins bake effectively in the oven instead of falling flat.