Are you generally careful with your cakes when you remove them from the oven? Do you gently set them on a cooling rack to settle in? Then what I have to say may come as a shock to you. Coddling your cakes may actually undermine their structure and a bit more tough love may give you the results that you actually want.The two cakes above were baked from the same batter and cooked to the same degree of doneness. In the above photo, the cake on the left shrunk in considerably from the sides (about 1/2 inch), wrinkled up on the top and became somewhat concave. The cake on the right shrunk in less than 1/4 of an inch and maintained a nice even, level top. So what’s the difference? The cake on the right I thwacked firmly on the counter upon removal from the oven, the cake on the left I placed directly on the cooling rack.
While this seems to make counterintuitive sense there is actually some valid science behind this “big bang” theory. Here is how it works:
- As your cake bakes, trapped gasses expand and liquids vaporize to create pockets of “air”.
- When the batter solidifies, proteins and starches form walls around the gasses and create individual cells.
- When the cake is removed from the oven the gas cells shrink as the temperature drops (according to the formula PV=nRT).
- If the individual cells remain intact, gas contraction occurs at varying rates and can lead to a sunken, shrunken cake.
- If you give the cake a good pounding, it essentially pops the small cells creating one uniform cavern of gas that can cool and shrink more consistently throughout the cake.
I know it seems a little scary to whack a delicate cake, but I have been doing this for years now and have never had it destroy a cake’s structure. This technique will not fix every sunken cake problem. There are times when a cake is not properly formulated and no amount of banging will help. But there are times when this method gives just enough edge to make a difference in the final structure.
So, get your frustrations out and give your cake a good knock-upside-the-pan. You may be very pleased with the results.