Bread flour is designed to be paired with yeast in order to produce a hardy structure in baked goods (usually breads). The amount of protein found in bread flour is higher, in order to produce more gluten, achieving the desired rise in bread. Because of this higher protein level, bread flour is able to absorb more liquid, allowing it to hold its shape and rise upward instead of outward.

You can substitute bread flour for all-purpose flour cup for cup. Just remember the texture will be more chewy than with all-purpose flour. If you’re substituting bread flour in a recipe that calls for another kind, remember that bread flour will absorb more water than other kinds of flour. You’ll want to increase the liquids in the recipe by a quarter or half cup to compensate.

In reverse you can substitue bread flour with AP flour. However, you will have to mimic the strengthening effect of bread flour by adding vital wheat gluten. Between 1 and 4 tablespoons of vital wheat gluten per loaf is all you need.

Bread flour contains 13 or more grams of gluten-forming protein per cup. By contrast, the all-purpose flour we generally use for baking contains anywhere between 9 grams and 11 grams these same proteins. This means that doughs made with bread flour will be stronger and more elastic, and the breads they make will be more dense and chewy.

This kind of flour is best used in recipes where you want that chewier texture. Pizza dough, artisan round loaves, bagels, and soft pretzels are all good candidates. You can also use this high-gluten flour when combining with low-gluten or gluten-free flours like rye, whole wheat, and buckwheat for better structure. I’ve also found it useful to use bread flour in recipes with a lot of “stuff” in the dough, like seeds and dried fruit.