Sometimes deceptively simple recipes can be the most exacting. That's certainly the case with angel food cake, which has a minimal list of ingredients but an infuriatingly large number of ways to go wrong. Just recognizing when it's done can be difficult, even for experienced bakers.
That's largely because of this cake's unusual airiness. Angel food is more like a meringue than a cake, with just enough flour and other ingredients to flavor and stiffen the whipped egg whites. This gives the cake its signature delicacy, but also means your experience with other cakes is less useful than you might think.
For example, you know a conventional cake is done when it starts to pull away from the sides of its pan. That doesn't happen with angel food cakes, because they're baked in ungreased pans. The batter clings to the sides of the pan, supporting the cake and helping it retain its structure and height as it bakes. You'll need to fall back on other methods to know when your cake is ready.
- Perhaps the most traditional way to check a cake is by inserting a toothpick or wooden skewer, and examining it when it comes out of the cake. If it's wet with batter or coated with stodgy, muddy crumbs, the cake probably needs a few more minutes. This technique isn't entirely reliable with angel food cakes, because the airy batter won't cling to your toothpick the way conventional cake batter does.
- A second test is to gently tap the top of an apparently finished angel food cake with your fingertips. If it springs back, the cake is fully baked. If your fingers leave an indentation in the cake, it needs to bake longer. In either case, there is some risk of collapsing the cake if you check it too soon. Don't start testing until the cake is fully risen in its pan and is richly golden on top. A well-risen angel food usually forms a few cracks at the top near the very end of its baking time, which makes for an excellent visual cue that it's time to test. In a full-sized tube pan, the cake will usually take about 45 minutes to bake.
They're used more often in meat cookery, but an instant-read thermometer provides the only sure way to know when your cake is done. Insert it into the thickest portion of your angel food cake, after you've already tried the toothpick or "tap" test, and are confident the cake is done. At a temperature of less than 195 degrees Fahrenheit it'll be done, but will retain slightly too much moisture. If you take it out at that point, steam escaping from the cake as it cools can loosen it in its pan and make it fall. Instead, continue baking a few extra minutes until its internal temperature reaches at least 205 F -- or as high as 209 F.
Clean the thermometer scrupulously before using it on your cake. No matter how good your last roast was, its flavor -- and more important, any bacteria -- are unwelcome in an angel food cake.
Once the cake is done, it needs to cool gently in its pan to keep that full height and delicate texture you've labored so hard to achieve. Carefully invert the pan, so gravity helps keep your cake at its full height. Stand a heavy-bottomed bottle in a warm, draft-free spot on your countertop and slide the tube of the angel food pan over it. If you've baked the cake long enough, it won't fall out of the pan. Instead, it clings to the ungreased sides until it's fully cooled.
Most angel food pans have tabs to hold the cake off your countertop once it's inverted, but in practice they don't give enough clearance. Steam builds up in the space between your cake and the counter, and can loosen it in its pan.
Once the cake is fully cooled, run a knife carefully around the inside of the pan to loosen it, and then lift out the pan's removable bottom to free the cake.