Cake Flour

• Cake flour contains much less gluten than bread flour. Because gluten is the main ingredient in flour and holds all of the other ingredients together, avoid using cake flour in place of bread flour. Doing so will have a very crumbly outcome. Cake flour is good for recipes that do not require cohesion as strong as that of bread, such as for cakes and soft cookies.
  
  

All-Purpose Flour

• All-purpose flour contains somewhat less gluten than bread flour. It is made from a variety of different wheats, whereas bread flour is made only from hard wheat. Its gluten content can be somewhat lower than that of bread flour: all-purpose flour may contain anywhere from 11 percent to 14 percent gluten, while bread flour is typically between 12 percent to 14 percent gluten. Using all-purpose flour may yield bread that is slightly denser and flatter.
  
  

Flour Combinations

• It is possible to substitute a mix of wheat gluten and all-purpose flour for bread flour. For every 3 cups of bread flour in a recipe, use 2 cups of all-purpose flour and 3 tablespoons of wheat gluten.
  
  

Is There a Perfect Substitute for Bread Flour?

• Not quite. It's possible to use all-purpose flour as the best substitute, or a combination of all-purpose flour with wheat gluten, but the results will never be quite the same as bread flour. Although all-purpose flour may be a passable substitute, it still contains nearly the same amount of gluten as bread flour.