How to Make a Cake Flour Substitute

Plenty of tender cake recipes call for cake flour, and plenty of kitchens do not keep it. The standard fix is simple: remove a little all-purpose flour and replace it with cornstarch. The cornstarch carries no gluten-forming protein, so it dilutes the flour down to something softer, closer to cake flour's tenderness.

This guide gives the measurements by weight and by volume, explains why sifting matters here more than almost anywhere else, and is honest about the limits. The substitute is very good in most butter cakes and cupcakes, and noticeably less good in a few delicate styles.

The formula

Cake flour is roughly 7 to 9 percent protein, all-purpose closer to 10 to 12 percent. Replacing about 13 percent of all-purpose flour with cornstarch brings the overall protein down into cake flour territory. By weight, that is 104 g of all-purpose plus 16 g of cornstarch for every 120 g of cake flour the recipe lists.

Weighing gives the most consistent result, because a cup of flour can vary by 20 g or more depending on how it is filled. If you use cups, spoon the flour lightly into the cup and level it before removing the 2 tablespoons.

• 120 g cake flour = 104 g all-purpose + 16 g cornstarch
• 240 g cake flour = 208 g all-purpose + 32 g cornstarch
• 300 g cake flour = 260 g all-purpose + 40 g cornstarch
• 1 cup cake flour = 1 cup all-purpose minus 2 tablespoons, plus 2 tablespoons cornstarch

Why the sifting step matters

Cornstarch is lighter and finer than flour, and it settles into pockets if you only stir. Uneven blending gives some parts of the batter extra starch and others extra gluten, which shows up as tunnels or tough streaks. Sifting the flour and cornstarch together three to five times, or whisking vigorously for a full minute and then sifting once, distributes it evenly and also aerates the mix, which mimics cake flour's light texture.

Make only what the recipe needs, or mix a larger batch and label the container. Shake or whisk it again before each use.

Where the substitute works well

In recipes where cake flour is chosen mainly for tenderness, the blend performs nearly the same: butter layer cakes, vanilla and chocolate cupcakes, funfetti cake, coffee cakes and soft cookies. Most tasters will not notice a difference, especially once the cake is frosted.

It is also useful for softening a recipe that came out tougher than you liked. Swapping in the blend for some of the all-purpose flour reduces chew without changing anything else in the formula.

Where real cake flour still wins

Bleached cake flour does more than lower protein: its treated starch absorbs more liquid and sets quickly, supporting batters with a high ratio of sugar and liquid to flour. Angel food cake, chiffon, and tall, very white high-ratio layer cakes rely on that. The substitute may produce a cake that rises well in the oven and then settles, or one with a slightly coarser, more open crumb.

If you bake these often, keeping a box of cake flour is worth it. For occasional cakes, the substitute still gives a respectable result, especially if you are careful not to overmix after adding the flour.

Other starch options

Arrowroot and potato starch both work at the same 16 g per 120 g ratio. Tapioca starch works too but can make the crumb faintly springy. Avoid rice flour or other flours in place of starch here; they contain protein and texture of their own and change the result.

For gluten-free cakes, this substitute does not apply, because all-purpose wheat flour is the base. Use a gluten-free flour blend designed for cakes instead.

Common questions

Can I use self-rising flour in place of cake flour?

Not directly. Self-rising flour contains baking powder and salt, and it is not as soft as cake flour. If you use it, remove the recipe's leavening and salt, but expect a different texture.

Can I make a big batch of cake flour substitute ahead?

Yes. Combine the flour and cornstarch at the same ratio, store it airtight, and whisk again before measuring because the starch can settle over time.

Does bread flour plus cornstarch work?

It softens bread flour but does not reach cake flour levels without replacing a large share with starch, which weakens structure. All-purpose is the better base.