Before we talk about bread flour, a review of how flour is made: Flour is made from finely grinding kernels of wheat, which itself falls under six classes: hard and soft, red and white, spring and winter. Hard wheats are, well, literally harder, and contain more protein and gluten than soft wheats. Flour milled from red wheat is favored for the robust flavor and rustic texture it lends to artisan loaves. Flour milled from white wheat, on the other hand, will lend loaves an airier, sponge-like texture. (Spring and winter merely refers to the growing season.)
Bread flour (or, flour that’s best for bread) is typically milled from hard red because of its high protein and gluten content. All-purpose and cake flour typically come from soft red or white wheat. Here’s how their protein contents stack up:
- Bread flour: 12 to 15 percent protein
- All-purpose flour: 9 to 12 percent protein
- Cake flour: 7 to 9 percent protein
So, why does protein matter? Gluten and gliadin are two proteins found in milled wheat that, once hydrated, combine to form a strong network. This elastic but extensible network provides structure, height, and chewy texture to loaves.
Use all-purpose or cake flour in a recipe that calls for bread flour (like bread) and you’ll get a “weaker” loaf—flatter, more tender or crumbly, less chewy than you might want. Conversely, if you use bread flour in a recipe that calls for all-purpose or cake flour (like, well, cake), expect a slightly denser, chewier, tougher end product.
I’m sure you’re starting to see a pattern here: bread flour is best for breads (pizza doughs, sourdough, enriched doughs), all-purpose for most baked goods (your scones, muffins, pie crusts), cake for tender treats (sponges, pound cakes, cupcakes).
Best for being the operative words here. Knowing the rough protein contents of each of your flours means you should feel empowered by all those half-opened bags in the pantry (extra-credit if you store flour in the freezer). Combine bread and pastry flour in equal parts for homemade all-purpose flour. Use pastry and cake flour interchangeably (pastry has slightly less protein content than cake flour). Swap bread flour in for the high-gluten flour required for extra chewy (QQ) Chinese noodles. Or experiment with bumping the protein content of your bread flour with vital wheat gluten.