Ever feel inspired to whip up a home-made cake, only to find yourself out of cake flour? Or maybe it seems a bit excessive to buy an entire bag of cake flour when you're only planning on making one cake. Instead of a special trip to the store, you can cut corners by making a substitute cake flour out of regular, all-purpose flour and corn starch.

Here's the formula: Take one level cup of all-purpose flour, remove two tablespoons, and then add two tablespoons of corn starch back in. (1 cup AP flour - 2 Tablespoons AP flour + 2 Tablespoons corn starch = 1 cup cake flour) Be sure to sift the flour to distribute the corn starch well before using it in your cake batter.

How does this work?

The primary difference between cake flour and all-purpose (AP) flour is the protein content (which becomes gluten). The protein content of cake flour is about 8%, while the protein content of AP flour is about 10-11%. When you're making cakes, you need a little gluten for structure but not so much that it gets tough and chewy, so you use a flour that's lower in protein. When added to AP flour, cornstarch will inhibit the formation of gluten while also giving structure and 'sponginess' to your cake.

Other starches like arrow root and potato starch can also be used, but our food science guru Harold McGee warns that cakes with these starches will cook more quickly and will often be more moist than those with corn starch.

(Photo and cake decorating by Erika Larson, with permission. Swans Down photo by Faith Hopler for The Kitchn.)

Cake Recipes:
• DIY Yellow Cake
• Dark Chocolate Cake
• Velvety Beet and Cocoa Cake

Related Links:
• Good Question: Pastry Flour vs. Cake Flour
• Pantry Basics: What is Cake Flour?
• Why From-Scratch Cakes are Healthier than Box Mix Cakes
• Why Did Our Cake Fall Flat?
• What Are Your Cooking Compromises?