Keep eggs at the right temperature. Since angel food cake uses no chemical leaveners, such as baking powder or soda, the meringue it’s based on must be ultra-stable. Separate your eggs when they are still cold, when the yolks are less likely to break and contaminate your whites. (Even the tiniest bit of fat from the yolks will keep whites from whipping up properly.) But then let them come to room temperature, when they will whip more quickly and more voluminously than when they’re cold.
Use cream of tartar. Adding 1/8 teaspoon per egg white will further stabilize the meringue, protecting it from turning grainy or collapsing if overbeaten.
Control your speed. A slowly whipped foam is sturdier than one whipped more quickly. Start at medium speed to break up the whites into froth, then increase to medium-high. It is tempting to turn the speed higher as you beat the whites to soft and then stiff peaks, but try to resist. Similarly, adding sugar slowly also creates a stronger meringue.
Sift the cake flour twice. The first time is to get rid of any clumps, and the second is to ensure it is well-aerated, does not weigh the batter down and can easily be folded into glossy, thick and voluminous egg whites.
Cool the cake upside-down after baking. Ideally, you want a tube pan with a removable bottom and with three metal feet. When the cake comes out of the oven, flip it upside down (either onto the pan’s feet or over a long-necked bottle if you have a footless pan) to cool completely. This is a little scary, but I promise the cake won’t fall out, and this helps guarantee that it won’t collapse as it cools.
These methods all add up to a quintessentially tall, light, melt-in-your-mouth angel food cake that’s a dream to eat — and make — whether you frost it or not.
