What's The Difference Between Cake Flour And Bread Flour?

You would expect that the flour aisle would be a very simple and self-explanatory section at the grocery store. After all, it's just milled wheat — right? Wrong. You'll find tons of different types of flour available for you to purchase, from 00 flour for pizza to gluten-free measure-for-measure flour for baking. It can be a bit overwhelming to select what you're looking for, given that all of the flours have very different properties that make them better suited for some uses than others. 

Two of the most common flour varieties available in the grocery store are bread flour and cake flour. If you looked at the two products in a bowl, chances are that you would not be able to tell the difference between them. But, if you added them to the same recipe, you'd likely see very, very different results. Here's the most important difference between these two types of flour and when you need to use each of them.

Close your eyes and envision the texture of a yellow cake. It's likely soft, easy to bite through, and breaks apart easily under the weight of your fork. This texture is likely due to the type of flour that the recipe is made with. 

Cake flour contains significantly less protein than other types of flour. It has around 6% protein, compared to all-purpose flour which has around 10% protein. The low protein content in this flour is due to the fact that it's made with soft wheat. As a result, when used in a recipe, cake flour doesn't develop the same protein, or gluten, structures as higher-protein flours. 

Cake flour's low protein content gives it its trademark soft bite. It's often called for in recipes where you're after this characteristic texture, such as in delicate cakes. However, it can also be used in tandem with all-purpose flour to soften the bite of a baked good while still giving it the structure it needs to hold together well. You might see something like this in banana bread since the cake flour will help lighten the dense loaf. 

Now, go ahead and close your eyes again and envision a ciabatta or a bagel pulled from the oven. When you bite into it, it likely has that characteristic, elasticky pull and chew factor. This texture is something that you can thank the high gluten content in the flour for. 

Bread flour contains a higher percentage of gluten than all-purpose flour — around 12%. When you mix the flour with water and start to aggravate that gluten, you get webs of protein. During the fermentation stage, as the yeast in the bread eats the carbohydrates, it starts producing air bubbles. This gives the bread its rise and structure. Without the gluten strands, you wouldn't be able to trap the bubbles, nor would you have the proper, toothsome structure. Some bread makers will cut the amount of bread flour in a recipe with all-purpose flour to give it a softer bite, but some recipes, like bagels, really need that high-protein bread flour to be successful.

When it comes to baking, gluten percentages matter. If you use cake flour in a recipe for bread, you're not going to get the same elasticky protein networks as you would with bread flour, and thus it will not have the same amount of rise or structural qualities you look for in a loaf. And if you added your bread flour to something like a delicate genoise sponge, you would be left with something more like a rubber tire. The different protein content allows the flours to perform different roles in your bake, which is why it's very important to pay attention to the type of flour you select. 

There are very few meaningful differences between cake and bread flour besides the gluten content. If you tasted the two raw (which we don't recommend, as raw flour can in fact make you sick), you would find very little difference between their taste and consistency. But, after you bake them into a recipe, you'll notice the difference between the two — and you might find yourself in the pantry double-checking that you did indeed buy the right kind of flour.