How to substitute all-purpose flour for cake flour

Not all flours are created equal.

All-purpose flour is just that. It means it can be used in myriad baked goods.

Cake flour is used for cakes and cookies when you’re looking for a tender crumb. Pastry flour is similar to cake flour and sometimes interchangeable. The high protein level of bread flour is what gives a crusty bread its structure.

When substituting all-purpose flour for cake flour, here’s the rule: use 1 cup of all-purpose flour minus 2 tablespoons and be sure to sift it. Some sources recommend replacing the 2 tablespoons of removed flour with 2 tablespoons of cornstarch. To make 2 cups of your own pastry flour, whisk together 1.3 cups all-purpose flour and 2/3 cup cake flour, says joyofbaking.com.

Cake flour is similar in texture to pastry flour. Both are soft, but if you rub the cake flour between your fingers, you can feel just how much softer it is than pastry flour. Protein levels in pastry flour are about 9 per cent; in cake flour, 8 per cent. The colour of flour also varies. Cake flour is bleached, so it’s nearly stark white and the texture is softer than all-purpose and even soften than pastry flour. Pastry and bread flours are cream-coloured.

Measuring

When it comes to measuring flour, how you do so matters. One question that comes up often regards when the flour should be sifted. If the recipe says “1 cup flour, sifted,” you measure, then sift it. If it calls for “1 cup sifted flour,” you sift, then measure.

Sifting aerates flours, therefore a wire whisk will also suffice as a sifting tool. But before you sift, think about how you measure the flour. Professional bakers weigh out flour and other ingredients to ensure their baked goods come out the same every time. If you’re not using a scale, spoon the flour into a measuring cup until it’s slightly mounded and then level it off with a knife.