Understanding Different Types of Flour: All Purpose, Bread, Cake

Gluten is the protein found in wheat. It is a combination of gliaden and glutenin (which together are 80% of the proteins in flour) in the presence of water. The amount of protein is the most important criteria for determining which flour to use. This is because it is gluten that gives dough and batters its structure. Low protein=tender, high protein=chewey.

 All purpose flour is the "go to" baking flour. As its name suggests it can be used for anything. It is made from a blend of hard and soft wheats. Hard (winter) wheats are high in protein. Soft (spring) wheats are low in protein. Most brands of all purpose flour have 3 grams of protein per serving.

Cake flour is made from soft wheat, and has 2 grams of protein per serving. It makes tender fluffy cakes.

Bread flour is made from hard wheat, and has 4 grams of protein per serving. Bread flour also often contains malted barley flour which improves yeast function and taste, and ascorbic acid to improve texture. Bread flour makes great bread, but all purpose is good too. My recommendation is to use bread flour where you want the final product to have some chewiness, like bagels, and to use all purpose flour where you want something more tender like rolls.

Note: King Arthur all purpose flour has 4 grams of protein per serving making it more similar to other brand's bread flour. Use it accordingly.