The Difference between Cake Flour and Pastry Flour | Yankee Kitchen
To put it simply, choosing the right flour is all about controlling the amount of gluten in your dough. So what is gluten? It’s a protein structure that makes dough both firm and elastic—think of a well-kneaded bread dough and how it feels like a big rubber band. Bread flour comes from “hard” flour, which has a higher protein content and thus produces more gluten, making it perfect for pizza dough, bread, and any other recipe that needs a little more elasticity and cohesion.
Pastry flour is made with “soft” flour, meaning it has much less protein content and produces less gluten. With the gluten bands, doughs made with pastry flour are tender, and flaky and don’t hold together as firmly. But that’s just the way we like it. After all, who wants a rubber piecrust? Cake flour has even less protein content than pastry flour but not by much. It has just enough protein to give the cake a little structure, but not enough to make it tough.
All-purpose flour, which is a blend of hard and soft flours, falls in the middle of this gluten spectrum, and it works well in most baked goods. Your cakes might not be quite as tender, but in most cases they’ll still come out beautifully. It’s all a matter of degree. Cookies, piecrusts, muffins, quick breads, and scones all do well with all-purpose flour.
Gluten development is also the reason why recipes instruct you not to overmix your dough. Once you add water (or any other low-fat liquid) to flour, gluten bands start forming and the more you knead or stir the dough, the more these elastic bands start connecting. If you are using all-purpose flour in a cake or piecrust, be sure to stop mixing just when everything comes together.