The Best All-Purpose Flour

Flour is a kitchen staple, and we use it in a variety of ways, from baking breads, cakes, cookies, and biscuits to making roux, sauces, and pastas to coating fried foods. While flours can be milled from barley, chickpeas, and tapioca (just to name a few options), we rely most heavily on all-purpose flour milled from wheat in our recipes. But despite the all-encompassing name, not all “all-purpose” flours are the same. In the test kitchen, we keep two types of all-purpose flour on hand: moderate-protein flour and high-protein flour, and we’ll often note a preference for one or the other in our recipes. We’ve found that these two products sometimes perform differently, and we employ each strategically when making baked goods to produce a desired texture. But what causes these differences, and how can such a simple ingredient create such varied outcomes? 

To find out, we took a closer look at all-purpose flour by rounding up five top-selling brands and using them to make our Easiest-Ever Biscuits and Olive Oil Cake recipes. We also had our resident bread expert, Cook’s Illustrated Senior Editor Andrew Janjigian, use each flour to make loaves of our Almost No-Knead Bread. Along the way, we asked tasters to evaluate the appearances, textures, and flavors of the baked goods. 

Bleached versus Unbleached Flour

All-purpose flour comes in both bleached and unbleached varieties. When flour is milled, pigments in the wheat called carotenoids (the same pigments that give carrots their bright orange color) give it a yellowish hue. While this color fades to off-white with exposure to oxygen over time, some manufacturers choose to speed up the process by chemically bleaching their flours with additives such as chlorine gas or benzoyl peroxide. While the U.S. Food and Drug Administration considers the chemicals used to bleach flour food-safe, several of these additives are banned in many countries, including China, India, and Brazil, as well as in the European Union.

Many brands make both bleached and unbleached versions of all-purpose flour, but we opted for the unbleached versions here since we’ve found in previous testings that bleached flours sometimes produce a bitter, metallic flavor in baked goods. We did include one bleached flour from White Lily, a favorite brand in the South that does not offer an unbleached version. While we didn’t detect any off-flavors in the biscuits, cake, or bread we made with the White Lily flour, we did notice that the baked goods we made with it were paler in color than those we made with the unbleached flours.

Protein Content of All-Purpose Flour

The protein content of wheat flours can range from ... read more