How to Measure Cake Flour to AP Flour

A sifter is nice, but not necessary when converting AP flour to cake flour.

Flour can be expensive, so it's nice to know that you can substitute two types of flour, if given proper measurements. Cake flour is made from soft wheat, and has anywhere from a 6- to 8-percent protein content. It is pre-sifted and ensures a light, silky texture in recipes that call for it. AP -- or all-purpose flour -- is made from a mixture of hard and soft wheat; has a protein content between 10 and 12 percent; and is not pre-sifted. The two are interchangeable if you make some adjustments.

Things You'll Need

• Cake flour
• AP flour
• Cornstarch
• Measuring cups
• Measuring spoons
• Butter knife
• Sieve or sifter
• Bowl
• Airtight container

Instructions

1. Measure 1 cup plus 2 tbsp. of cake flour for every cup of AP flour called for in your recipe. Level each amount by swiping the back of a butter knife over the top of the measuring cup/spoon so that the flour is flat. Since cake flour is more aerated and less dense than AP, the extra cake flour creates the equivalency.

2. Level off 1 cup of AP flour, but keep it in the measuring cup and do not dump it into your recipe yet. This AP flour is about to become cake flour before your very eyes.

3. Remove 2 tbsp. of AP flour from your measuring cup and put it back wherever you store your all-purpose flour.

4. Dump the remaining AP flour into a sieve or sifter placed over a mixing bowl. If you have a sifter, feel free to use it, but shaking a sieve full of powdered ingredients works just as well, and is commonly used in professional kitchens, since sieves are multipurpose.

5. Add 2 tbsp. of cornstarch to the AP flour in your sifter or sieve. Sift the flour or shake the sieve gently over the bowl to aerate and mix the all-purpose flour and cornstarch. Repeat this six times so that the mixture is fully incorporated. You have now made 1 cup of cake flour from AP flour and cornstarch.

6. Store your homemade cake flour in an airtight container for later use if you are not using it right away.

Tips & Warnings

• All flours, even ones that say they are pre-sifted on the package, settle over time. The longer they sit on the shelf -- whether it's in a store or your cupboard -- the more they settle. When making any recipe that uses baking powder or baking soda as leavening, sift the flour before use -- even if it is homemade cake flour. Your recipes may also suggest this, but do it even if they do not. This will ensure the light texture in your baked goods that you want.

References

• "The Professional Chef (Eighth Edition)"; Culinary Institute of America; 2006
• Joy The Baker: How To Make Cake Flour