Preheat oven to 350 degrees F. Have an ungreased 16-cup tube pan ready.
Sift half of sugar with flour and salt. Repeat 5 times.
Beat egg whites on low until frothy, then add vanilla extract and cream of tartar. Increase to medium, adding remaining sugar 1 tablespoon at a time. Increase to medium-high and beat until stiff, glossy peaks, scraping sides and bottom of bowl once or twice as needed. Sift about ¼ cup flour mixture on top and fold gently to incorporate; repeat until all flour is used.
Spoon into tube pan, smooth the top, then run a knife through batter to break any air bubbles. Bake until skewer inserted halfway between edge and center comes out clean, about 35 to 40 minutes.
Cool upside down at least 1 hour. Run knife around edge and turn out onto serving dish; run knife around bottom and release. Place on a serving platter, slice and serve. Angel food cake is best the day it is made, but can be stored for up to 2 days at room temperature, wrapped well in plastic wrap or stored in an airtight container.
Notes
Equipment: A tub pan is essential for this recipe; you want one that has a 16-cup capacity - this is the one I use.
Do NOT Grease the Pan: This is very important! The cake needs to cling to the sides of the pan in order to rise, as well as during the cooling process. This ensures that the angel food cake will be high and retain its volume. If your tube pan does not have a removable bottom, then line the bottom only with parchment paper for an easier release.
Egg Whites: Use real, fresh eggs for this recipe. Egg whites in a carton have been pasteurized, which can result in their inability to be whipped to stiff peaks.
Cooling: If the pan has little feet on the bottom, you can simply set it upside down to cool on a wire rack. However, if it does not have feet, then you will want to invert the pan onto the neck of a glass bottle for the cooling process.
Stand Mixer Alternatives: While the mixing is easiest with a stand mixer using a whisk attachment or a hand mixer, you can whisk the egg whites by hand using a balloon whisk and elbow grease!
Number of Eggs: How many eggs you use will vary based on the size of the egg and the size of the yolk in each individual egg. I typically only need 10 eggs to get 1½ cups of egg whites, but most recipes say 11 or 12 is the average.
Separating Eggs: Eggs separate easier when they are cold, and if there is any yolk in with the egg whites, it will prevent them from whipping up into stiff peaks, so I recommend separating and measuring the eggs while cold, then allowing them to come to room temperature before proceeding with the recipe.
Different Flavors: You can substitute almond extract, orange extract, lemon extract, or use them in combination with the vanilla to adjust the flavoring. Be sure to check the label on them, however; if there is any oil (which is sometimes included in flavored extracts) it can prevent the eggs from forming stiff peaks.
Slicing the Cake: It’s super important that when cutting angel food cake, you use a sharp, serrated knife and a gentle sawing motion (I use my favorite bread knife). Using a straight-edge knife and/or cutting straight down will smush the cake.
Make-Ahead: Angel food cake can be prepared one day in advance; once cooled completely and removed from the tube pan, cover with plastic wrap and keep at room temperature.
Freezing Instructions: Angel food cake can be frozen by wrapping it (either the whole cake or individual slices) tightly in plastic wrap, then in aluminum foil. Place in a freezer-safe bag or container and freeze for up to 4 months. Thaw at room temperature.