Of all the things gluten does well, tender, light, and fluffy angel food cake belongs nowhere on the list. Thanks to the sheer volume of water found in egg whites, angel food cake toughens up like shoe leather in the presence of gluten. So much so that the single most important ingredient in the recipe's evolution is chlorinated cake flour (a.k.a. bleached cake flour): an ultra-low-protein alternative whose gluten-forming potential is further hampered through a process that fundamentally changes how its starches and proteins behave.
While I've got no gripe with the process (nor does the World Health Organization), some folks prefer to avoid bleached cake flour, and others live in parts of the world where it's unavailable. The obvious choice would seem to be unbleached cake flour, but I have no interest in adapting my recipe to combat its strength.
I mean, why fight gluten when you can avoid it altogether?
Some recipes (say, for baguettes or pizza) throw a fit when you try to take away the wheat flour, but not angel food. It's always chafed under the tyranny of gluten, and it's glad to see it go. Besides, angel food cake is so high in protein from egg whites, it has enough strength to stand on its own—just like the firm, sliceable meringue atop your favorite custard pie. With that kind of underlying structure, all angel food cake really needs is enough starch to keep its moisture in check, ensuring that it bakes up airy and light rather than eggy and dense.
The trick is diversification, which prevents all that starch from tasting chalky. I'm not talking about any sort of 37-flour blend, just a simple collection of gluten-free basics: cornstarch, white rice flour, tapioca starch, and coconut flour.
Cornstarch is pure starch and contains no protein, giving it a virtually unquenchable thirst. It's also sturdy enough to endure temperatures up to 212°F, making it fantastic for binding a high-moisture, high-protein cake. Doesn't hurt that it's light, white, and mild, too, in keeping with the cake's natural profile.
On the flip side, it can seem a little chalky on its own, so it's best paired with more palatable types of flour and starch. White rice flour works well because it also has a mild flavor and an appropriately angelic hue. It's as absorbent as wheat flour, which means that there's just a little bit less math to do in recalculating ratios of liquid to dry ingredients when converting standard recipes to gluten-free. Unfortunately, while its slight grittiness disappears in crispy cookies and steamed cakes, the relatively low baking temperature inside an angel food cake (about 206°F) tends to preserve that coarse texture.
Enter tapioca flour, likewise snowy-white, starchy, and mild. Unlike cornstarch or white rice flour, however, it's free from any sort of chalky taste or gritty residue because its granules swell and burst at temperatures above 140°F, rendering their particle size something below our threshold of perception. While that's great for amazingly tender lemon meltaways and alfajores, the sudden loss of water-binding capacity can lead to collapse in cake.
That's where coconut flour comes in, which balances tapioca's weakness with its freakish strength. A single ounce is all that's needed to pick up the slack, absorbing enough moisture to ensure that my angel food cake never seems heavy or wet.
Once you've got that blend of starches and flours squared away, the ingredients and technique are identical to those for my traditional angel food cake. It's a rather unconventional method, but easy to master. Simply throw equal parts egg whites and sugar into a bowl, then make like Michael Jackson and beat it.
This gluten-free adaptation is as light and fluffy as the original, and quite a bit more tender. So, whether you're avoiding gluten in general, or bleached cake flour in particular, this recipe is the solution you've been waiting for.