Charlene asks via email:
"I just made Fine Cooking's Angle Food Cake. The cake was baking and looking beauitful, it was about 1/2 inch above the pan, then the last 5 minutes of baking it colasped. What happened?"
This is one of those cases that called for additional follow-up, so we had some back and forth. Unfortunately, as the recipe was originally developed 14 years ago, it was unlikely that the test kitchen would remember much from this one particular cake, but there were clues in what Charlene wrote above.
The big concern is the falling, naturally. There are plenty of reasons why a cake that is primarily egg foam will collapse, though it doesn't have to be that way. My initial follow-up was to verify that she didn't open the oven in the middle of baking, which would have been potentially disastrous, and if she perhaps set off any explosives nearby.
The oven remained closed, and there were no explosives, but right around the time of collapse her washing machine went into its spin cycle, and she reports that one can definitely feel when the washer is on its spin cycle from the kitchen, so I am certain that this contributed to the collapse.
It's hard to say if that was the only contributing factor, and there was still at least one more mystery: why did the cake rise so high? It's certainly not a bad thing to have a cake rise high, and maybe a half-inch wasn't all that much, but I still had suspicions. The thing about angel food cake is that all of the rise comes from heating the air that's trapped inside the bubbles formed by whipping the egg whites. There's no yeast releasing additional gasses, nor is there any chemical leaveners that you can put too much or too little in. So there needs to be something to contribute to extra rise that isn't obvious.
So I asked Charlene, "Was it raining the day you made the cake?" And many of you may be wondering, "why would rain matter? Is humidity going to make the cake rise more?" No, it won't. But the cake did rise more, and Charlene told me that yes, it was raining. So what happened?
Think of a home weather station. There are generally up to three components to it: thermometer, to tell the temperature, a weather vane, to tell the direction of the wind, and a barometer, to tell the atmospheric pressure. The purpose of the barometer is to predict rain, which it does by showing that the atmospheric pressure is dropping. So, when it rains, there is less atmospheric pressure.
All of that leads to one of my favorite food facts: when there is less atmospheric pressure, a cake can rise higher, because the atmosphere isn't pushing as hard on the cake, so it's easier for the cake to rise. I love that. So if you bake a cake when it's raining, the cake will rise higher. This goes for other baked goods as well.
Did the extra rise contribute to the cake falling? It's hard to say. It makes a certain amount of sense that the structure was stretched farther than it normally would, then when the washer's spin cycle came on, it shook the pan for a minute or so and caused the structure to collapse. It makes sense, but we may never know for sure.
There are certainly plenty of tips for making a successful angel food cake. Most of them are discussed in this handy article on tips for successful angel food cake baking. Other tips I might add are:
- Ensure that your oven temperature is calibrated properly.
- Pay attention to your recipe's recommendations for the speed that you whip your whites. Going slower or faster is not necessarily helpful, and may result in a less stable product.
Overall, I think this particular situation was something of a fluke. Hopefully Charlene, you can make another cake without the washer interrupting and it will come out beautifully. Please let us know how it goes.