All-purpose flour is like a one-size-fits-all dress. It’s adequate for most occasions and perfect for some, but every now and then it’s just plain wrong. All-purpose isn’t for pizza dough, and one-size-fits-all isn’t for prom night.
The trick, of course, is knowing when all-purpose flour is right, and which flour to use when it’s wrong. That’s where science comes in – chemistry, to be specific. But don’t panic! You won’t need your periodic table or your gas chronometer. You just need to know a little about wheat.
The protein content of wheat flour is probably the single biggest variable in the outcome of your baked goods (assuming your yeast is alive and you know baking powder from baking soda), and that content is partly determined by the wheat itself – hard wheats are high in protein, soft wheats are low – and partly by the processing. Most wheat protein is in the form of gliadin and glutenin, which, when water is added, combine to form gluten, the magic compound responsible for the crumbliness of cakes (when there’s less of it) and the chewiness of pizza dough (when there’s more of it). Gluten forms an elastic network that traps the carbon dioxide created by the leavening agent. The more gluten, the stronger the network, the bigger the air bubbles and the more structured the end product.
You’d think, given the importance of protein content, that flour makers would print it in big numbers right on the bag. But nooooo. Although the kind of flour it is gives you a clue (see sidebar), most mills make you call them or go to their web site for that critical piece of information.
The Whole (Wheat) Truth
Whole-wheat flour is a slightly different animal. It generally has a high protein level, but it doesn’t act like a refined high-protein flour. As its name implies, whole-wheat flour uses the entire grain – bran, germ, and endosperm. (Refined flour uses only the endosperm.) Not only does the bran interfere with the creation of gluten, once that gluten is created, sharp little pieces of bran tend to pierce the bubbles that hold in the gas, popping them like a balloon. Voila! Paperweight. To avoid that problem, work with recipes specifically designed for whole-wheat flour; substituting whole-wheat in a recipe calling for refined flour can yield disappointing results.
In general, trying recipes that use different flours is a good way to get a sense of what they can do. Once you’ve got that sense, feel free to experiment. When the worst-case scenario is a caky brownie, you’ve got nothing to fear.
Wheat, Wheat, Don’t Tell Me: Which Flour to Use?
There are no hard-and-fast rules; this is only a place to start. One good guideline is that high-protein flours work well with yeast, and low-protein with baking powder or soda. Beyond, that, though, it’s all about preference. When in doubt, use what you have in the house.
Cake Flour - 5-8 percent protein. Use for cakes, sugar cookies, scones, biscotti, Madeleines, recipes with a high sugar-to-flour ratio
Pastry Flour - 8-9 percent protein. Use for pastry, biscuits, pie crust (similar uses to cake flour)
All-Purpose Flour - 9-12 percent protein. Use for cookies, quick breads, pancakes, dumplings, cobbler and crumble topping, tart and cheesecake crust, brownies, anything that doesn’t need a fine crumb or a firm structure
Bread Flour - 12-13 percent protein. Use for bread of all kinds: ciabatta, English muffins, focaccia, brioche, breadsticks
High-Protein Flour – 13-15 percent protein. Use for bagels, pizza dough
—By Tamar Haspel