Baking is a science, but that doesn’t mean it’s impossible to make substitutions. With some guidance, you’ll be able to substitute different flours into a single recipe. But you’ll just want to keep a few things in mind, notably protein content and the moisture. This guide is by no means comprehensive — it may not answer your questions about oat flour — but consider it a starting off point to help you understand what you’re working with.
Tips for Successful Substitutions
Use a flour with a similar protein content. Protein content affects a baked good’s final texture and crumb: Treats made with higher-protein flours tend to be denser, while those made with lower-protein flours are lighter and softer.
Here are some common flours and their protein contents:
Whole-wheat: 14 percent
White whole-wheat: 13 percent
Bread: 12 to 13 percent
Spelt: 12 to 13 percent
All-purpose: 11 to 12 percent
Whole-wheat pastry: 9 to 11 percent
Pastry: 8 to 9 percent
Cake: 6 to 8 percent
Substitute by weight whenever possible. If measuring by volume, carefully scooping the flour into the measuring cup, overfilling it, then leveling it off will yield a more accurate measure.
If substituting a flour with a higher protein content (a “stronger” flour) or lower protein content (a “softer” flour), know that the moisture of the dough or batter will most likely be affected. When a stronger flour is substituted in, it’s at risk of being too dry. Similarly, if a softer flour is used, it’s at risk of being slightly too wet. If it’s dry, add 1 teaspoon water at a time and combine. If it’s too wet, add 1 to 2 teaspoons of flour at a time until you reach your desired texture.
Substitutions by Flour Type
Whole-wheat flour has the highest protein content on our list. For that reason, when substituting it for all-purpose, use 50 percent whole-wheat, and 50 percent of another flour, preferably all-purpose, pastry flour or spelt, to avoid a dense result. If you want to use only whole wheat, you’ll need to add more water.
At 12- to 13-percent protein content, bread flour is stronger than all-purpose flour, but it can generally be substituted for all-purpose, and vice versa. However, it’s important to remember that bread flour’s increased protein could result in a dough or batter that’s dry, so you may need to add water. Make sure not to overmix: Its higher protein content can also lead to a tougher result if not mixed in gently.
You can use all-purpose flour in place of bread flour, but all-purpose’s lower protein content means it may yield a slightly wetter dough or batter. Use all-purpose in conjunction with whole-grain flours to help reduce the overall protein content in the recipe — for example, a half whole-wheat and half all-purpose mix to avoid dense muffins. And a note: Gluten-free all-purpose flour blends perform similarly to regular all-purpose, and can generally be substituted one-to-one. These blends are great in everything from cookies to quick breads to scones, so if you can’t get all-purpose flour, it’s worth picking up a bag of a gluten-free blend, if it’s available.
With a protein content of 12- to 13-percent, spelt is closest to all-purpose in protein content, making it a delicious (and whole grain!) substitute that can easily be swapped cup for cup. Keep an eye on the consistency of the final dough or batter: It may be dry and need more moisture.
Pastry flour is a softer flour that substitutes well for all-purpose in any recipe where tenderness is the goal, like muffins, quick breads and cakes. If you can find it, whole-wheat pastry flour is an even better swap for all-purpose. Similarly, you can also use all-purpose flour in a recipe that calls for pastry flour.