Updated 30 July 2026 · Written by MKB Team
To make a cake flour substitute, measure 1 cup of all-purpose flour, remove 2 tablespoons, and replace them with 2 tablespoons of cornstarch, then sift several times. The cornstarch lowers the protein and the sifting lightens the flour, giving the tender, fine crumb that cake flour is prized for.
1 cup cake flour = 1 cup all-purpose flour minus 2 tbsp, plus 2 tbsp cornstarch, sifted well.
The Homemade Ratio
Cake flour is low in protein, which gives cakes a soft, delicate crumb. To mimic it, take a cup of all-purpose flour, remove two tablespoons, and add two tablespoons of cornstarch in their place. Sift the mixture several times to blend it and add lightness.
Why It Works
Cornstarch has no gluten-forming protein, so replacing part of the flour with it lowers the overall protein, closer to real cake flour. Sifting aerates the mix for a finer texture. For the difference between flours, see bread flour vs all-purpose. Weigh ingredients on a kitchen scale for consistency.
Cake Flour (per 1 cup)
| Ingredient | Amount |
|---|---|
| All-purpose flour | 1 cup minus 2 tbsp |
| Cornstarch | 2 tbsp |
| Method | Sift 3 to 4 times |
Frequently Asked Questions
How do I make cake flour?
Remove 2 tablespoons from 1 cup of all-purpose flour, add 2 tablespoons of cornstarch, and sift several times for each cup of cake flour needed.
What does cake flour do?
Its low protein gives cakes a soft, fine, tender crumb. The cornstarch swap lowers protein to imitate that effect in all-purpose flour.
