No Cake Flour? Make Your Own in 10 Seconds (With Exact Measurements)

Your recipe calls for cake flour. You don't have any. The store is closed. Don't panic - you can make your own in 10 seconds.

The Formula

For every 1 cup of all-purpose flour, remove 2 tablespoons and replace with 2 tablespoons of cornstarch.

In grams: for every 125g of AP flour, use 105g AP flour + 20g cornstarch.

Why It Works

Cake flour has less protein (7-8%) than AP flour (10-12%). Cornstarch has zero protein. By replacing some AP flour with cornstarch, you dilute the overall protein content, mimicking cake flour.

Step by Step

1. Measure 1 cup (125g) of all-purpose flour.

2. Remove 2 tablespoons (about 20g).

3. Add 2 tablespoons (about 16g) of cornstarch.

4. Sift together 2-3 times to distribute evenly.

Does It Work Perfectly?

It's close - about 90% there. The protein content will be similar to cake flour, but the milling is different. Real cake flour is more finely milled, which affects texture. For most home baking, the difference is negligible.

When NOT to Substitute

If you're making a recipe that's specifically designed for cake flour (like a delicate genoise or angel food cake), buy real cake flour. The substitution works great for everyday cakes and cupcakes, but not for recipes where cake flour is the star.

Bottom Line

1 cup cake flour = 1 cup AP flour minus 2 tbsp + 2 tbsp cornstarch. Sift together. Bake as directed. It's not perfect, but it'll save your recipe in a pinch.