All-Purpose Flour vs. Bread Flour vs. Pastry Flour vs. Cake Flour: What’s the Difference?
If baking is a science, then your ingredients are the periodic table, and flour is the most important element. The type of flour you use in your baking can greatly affect the outcome of your cakes, cookies and pies, so it helps to know what you’re working with.
Before you can understand the differences between types of flour, you need to know how they’re made. Flour is made from grinding wheat (duh). The seed head, or the part of the wheat plant that gets ground, is made up of 3 parts: the endosperm, the bran and the germ. A flour labeled “whole wheat” is made from all three parts, while a white flour is made only from the endosperm, which makes it more shelf stable and tender. It’s difficult for whole wheat flours to develop the same level of gluten as non-whole wheat, which is why baked goods made with whole wheat tend to be more dense than those made with white flour.
All-purpose flour is made with only the endosperm, which makes it more shelf-stable than flours made from grinding the whole seed head. It has less fiber and protein than a whole-wheat flour, but it’s great for middle-of-the-road baked goods that aren’t particularly delicate, like cookies, brownies and quick-breads.
Bread flour is made out of “hard wheat” varieties, which give it a higher protein content. That protein content leads to better gluten development, which is useful in anything that is supposed to come out chewy and textural, like bread or bagels. Avoid using bread flour in anything that is supposed to be tender, like cakes and pastries.
Pastry flour is milled to a finer texture than all-purpose flour, and is made with soft wheat for a lower protein content, which helps baked goods like pie crusts and pound cake recipes produce very tender results and a fine crust. Avoid using pastry flour for anything that demands structure, like bread doughs or pastas.
Cake flour is the most finely milled flour you’ll find, with a similar level of protein content to pastry flour. It is almost always bleached, which contributes to its ability to bake to a very high rise. Use it in places where a highly-risen, tender result is desired, like sponge cakes.
Bonus: Bleached vs. Unbleached
Bleached flours are treated with chemicals like chlorine or benzoyl peroxide, that damages the starch and protein content. It is generally easier to work with, absorbs more liquid, and rises better than unbleached flour. Most types of white flour are available bleached or unbleached.