I don’t know about you, but I don’t always have cake flour on hand, especially when I need it. And sometimes, all purpose just isn’t. Or is it? Of course it is. It’s too much! It’s too much gluten! But unless you’re making bread, you don’t want that. All purpose flour contains about 11% protein; cake flour has about 7%. Doesn’t seem like much of a difference, but certain recipes (say, angel food cake), demand cake flour because the lower protein content produces the absolutely necessary light and airy result. Other recipes are more lenient, and can accept a substitution. For those recipes, read on and make your own cake flour.
For every one cup of cake flour that a recipe requires, a mix of all purpose flour and cornstarch can be combined to make a substitute. Cornstarch contains no gluten, and serves to cut down on the total protein in the mixture. It’s certainly not a perfect swap, but will work in most recipes, and if you have no other option, it’ll do. If you have time, however, run out to the market and buy some cake flour.
Materials (for 1 cup flour)
1 cup minus 2 tablespoons all purpose flour
2 Tbsp cornstarch
Protocol (the easiest method)
Place two tablespoons of cornstarch into a measuring cup, and add all purpose flour to the 1 cup mark. Sift three times to fully incorporate the two components into one another. You can also scoop out a full cup of all purpose flour, remove 2 tablespoons, and then replace them with 2 tablespoons of cornstarch, but that’s way too much math. Add, subtract, then add again… No thanks. I’m not a mathematician, and I hope you don’t have a parabolem with that.