Cake flour is a specialty flour that is low in protein and very finely ground. The flour produces cakes and other baked goods with a finer, softer texture than all-purpose flour.
When a recipe calls for cake flour, you'll get the best results following the instructions and using real cake flour. However, if you're in a pinch and need a substitution, a combination of all-purpose flour and cornstarch will do the trick.
How to Make a Cake Flour Substitute
If you don't have cake flour on hand and need to make a cake in a hurry, use the following swap:
- For every 1 cup of cake flour, use 1 cup minus 2 tablespoons of all-purpose flour and add 2 tablespoons of cornstarch.
- Sift together and proceed with the recipe as written.
Arrowroot starch or arrowroot powder will also work in place of the cornstarch but may shorten the baking time for your cake as well as produce a moister result. Arrowroot is a popular ingredient in gluten-free baking and can be used as a thickener similar to cornstarch.
What Makes Cake Flour Special?
Cake flour is a finely milled flour made from soft wheat that's usually bleached. It's used in cakes and cupcakes to produce a fine, tender crumb and fluffy texture. Because the texture is finer, cake flour weighs less than all-purpose flour and has a slightly lower protein content. In fact, it has the lowest protein content when compared to other flours like all-purpose, whole wheat, and bread flour. Cake flour has five to eight percent protein content as compared to all-purpose flour's 10 to 13 percent.
In baked goods, the gluten protein helps all of the ingredients bind together. The more protein in a flour, the more sticky and thick your batter or dough will be. Bread flour is high protein, creating a glutinous dough that makes for deliciously chewy bread with a crispy crust. Cake flour is on the other end of the protein spectrum, instead creating an airy batter with a dense crumb.
While all-purpose flour can be used in any baking recipe with at least moderate success (hence the name "all-purpose"), cake flour produces the fluffiest, lightest cakes possible. Using the homemade substitution won't produce the exact same results as using cake flour, but it will come close.
How to Make All-Purpose Flour With Cake Flour
If you end up with plenty of cake flour but are out of all-purpose, you can perform a similar swap in the opposite direction. Try this substitution for your baked good:
- For every 1 cup of all-purpose flour called for in the recipe, use 1 cup plus 2 tablespoons of cake flour.
This accounts for the difference in weight between cake and all-purpose flour. This tweak will not solve cake flour's lack of protein, so it is not an ideal choice for a glutinous bread. It will work with a minimal difference for cakes, muffins, and quick breads.