Cake Flour vs. All-Purpose Flour (The Difference)

Cake flour is fine-tuned for cake perfection. So how is it different from all-purpose flour, and can you use the two interchangeably?

You want to bake a cake, and the recipe you found in that favorite cookbook of yours specifically calls for cake flour. But all you have in the pantry is all-purpose flour.

Or maybe it’s the other way around? You want to make a loaf of bread or a homemade pizza, but you only have cake flour left from the cake you made last week for the kids’ birthday party.

It’s good that you stopped by, then! Because whatever brought you here, we have what you’re looking for: a practical comparison of cake flour and all-purpose flour, along with tips and ratios on how to substitute one for the other.

What Is Cake Flour?

Cake flour is a flour with a fine, powdery texture and white color. It has a low gluten content of 7-8% and, as the name suggests, is used for cakes and fine baked goods like brownies, cupcakes, muffins, and scones.

Cake flour is made from soft wheat. With plenty of starch and little protein, cake flour produces light, tender, and delicate baked goods that barely hold their shape when held in the hand and melt in the mouth when eaten.

What Is All-Purpose Flour?

All-purpose flour, also called “plain flour,” is a general purpose flour for breads, pizzas, and pastries. Depending on where you live and who you buy your flour from, all-purpose flour can contain anywhere from 7.5 to 12% gluten.

In the Southern US, Pacific Northwest, and Canada, for example, all-purpose flour contains anywhere from 7.5 to 9.5% gluten. In the rest of the US, all-purpose flour has 11 to 12% gluten.

In Europe, the protein content of all-purpose flour is about 10%, though every country has its own traditions and classification system—making comparing it difficult to compare apples to apples.

All-purpose flour is made from a mixture of soft and hard wheat. Because it’s a general purpose flour that’s supposed to work equally well for pasty and bread, it’s stronger than cake flour and weaker than bread flour.

Cake Flour vs. All-Purpose Flour

	Cake Flour	All-Purpose Flour
Wheat	Soft wheat	Soft and hard wheat
Protein Content	7-8%	7.5-12%
Ash Content	0.3%	0.4%
Uses	Brownies, cakes, cupcakes, muffins, scones, others	Bread loaves, pizza pies, pastry, others

Wheat

White flour is made from wheat, and all wheat crops fall into one of two categories: soft wheat and hard wheat. Soft wheat has less protein, and so the doughs made from it tend to be fall-apart soft. Hard wheat has more protein and therefore produces more elastic and workable doughs.

Cake flour is made from soft wheat, while all-purpose flour is made from a mixture of soft and hard wheat.

Protein Content

Flour consists mainly of starch, some protein, and a tiny amount of minerals from the wheat kernel.

The protein in flour, called gluten, gives strength and structure to the dough. Generally, flours containing more protein yield more stretchy and chewy doughs, those with less protein yield delicate and tender doughs.

Low-protein flours are called weak flours, and high-protein flours are called strong flours. Cake flour is about as weak as wheat flour can be, it has an even lower gluten content than pastry flour! All-purpose flour is neither weak nor strong; it’s right in the middle for reasons of versatility.

Ash Content

Another way to compare two types of flour is to look at their ash content. The ash content is the amount of minerals from the germ, bran, and endosperm left behind if you were to burn 100 grams of flour.

As a general rule, more refined flours have a lower ash content because they contain less germ, bran and endosperm; less refined flours have a higher ash content because they contain more of them.

Cake flour has an ash content of 0.3%, while all-purpose flour has an ash content of 0.4%. This means that cake flour is slightly finer than all-purpose flour, which makes it finer and whiter.

Substituting One for the Other

You can substitute all-purpose flour for cake flour, and vice versa, but there’s a trick to doing it right.

Substitute All-Purpose Flour for Cake Flour

Since all-purpose flour is stronger than cake flour—meaning it has a higher gluten content—you need to weaken it by adding powederd starch, such as cornstarch, effectively reducing the gluten content in proportion to the starch content.

How it works:

For every 1 cup of cake flour, measure 1 cup of all-purpose flour, take out 2 tablespoons, and return them to the flour bag. Add 2 tablespoons of cornstarch and mix well with dry hands to incorporate before adding water.

Substitute Cake Flour for All-Purpose Flour

Since all-purpose flour absorbs more water than cake flour, you need to add more cake flour than all-purpose flour to the dough mix. Otherwise, your dough would turn out a wet, sticky mess.