Do You Need King Arthur? And Why Mix Bread Flour with All-Purpose Anyway?
Matt asked a great question on the Poolish Pretzel Loaf recipe, and I know he’s not the only one wondering. So let’s break this down. First, the brand name question. No, you don’t have to use King Arthur. Or Bob’s Red Mill. Or any specific brand. When you see “KA bread flour” in one of my recipes, that’s just because I happened to be testing with what was on my counter that day. What actually matters is the protein percentage on the bag. Bread flour generally runs 12 to 14 percent protein. All-purpose runs 9 to 11 percent. That number is what’s doing the work, not the logo. Kirkland AP, Gold Medal AP, store brand AP. They all behave the same way if the protein is in the same range. Flip the bag over, look at the nutrition panel, divide grams of protein by serving size in grams, and you’ve got your number. Now the science part. Why mix two flours at all? Protein builds gluten. Gluten is what traps the gas your starter or yeast produces. More gluten means a stronger, chewier structure. Less gluten means a softer, more tender crumb. When a recipe calls for a mix of bread flour and all-purpose, I’m dialing in a specific protein target somewhere between the two. Not as chewy as a pure bread flour loaf, not as tender as a pure AP loaf. Right in the middle. For something like a pretzel loaf, you want enough chew to feel like a pretzel, but not so much that it fights you when you bite into it. The mix gets you there. So what about Matt’s specific question? If he uses only Kirkland AP, will it affect the crust? Yes, but probably not in the way you’d expect. The crust color and crispness come from the bake — the steam, the temperature, the time. AP flour will still give you a beautiful crust. What changes is the interior. You’ll get a softer, slightly less chewy crumb. Some people prefer that. If you want to push the protein up, vital wheat gluten works. The general rule is about 1 teaspoon of vital wheat gluten per cup of AP flour adds roughly 1 percent protein. So if your AP is 10 percent and you want it closer to bread flour territory, a tablespoon or so per pound of flour gets you there.