Cake flour is made from soft wheat varieties, is more finely milled, and has less protein than all-purpose or bread flours.
Specifically, it has less gluten protein, which makes for lighter, fluffier baked products.
Although successful cakes can be made from all-purpose flours and most home baking recipes call for this, they may be a bit tougher than cakes made with cake flour.
Keep in mind, as well, that all-purpose flours are not all the same.
Most are made with a blend of hard and soft wheat, giving a moderate protein content. But, as mentioned here, all-purpose flours in the Southern United States tend to be made with soft wheat, yielding a lower protein flour, about 8 percent, the same as most cake flours.
If you have a typical brand of all-purpose flour such as Pillsbury, Gold Medal, or King Arthur, you can successfully use them to replace cake flour by using the simple conversion below.
Also included is how to replace all-purpose flour with cake flour, but this will not tend to be as successful, if you are trying to bake something with a bread-like consistency, as the protein content will be too low.
How to Replace Cake Flour with All-Purpose Flour
- To replace 1 cup of cake flour with all-purpose, use 1 cup minus 2 tablespoons of all-purpose flour, and add 2 tablespoons of cornstarch.
- To replace 1 cup of all-purpose flour with cake flour, use 1 cup plus 2 tablespoons cake flour. It is also possible to add store-bought gluten bread enhancer to cake flour, but we are assuming that this is an emergency substitution and you do not have this ingredient.