Flour is an important pantry staple in so many baking projects — from cookies and cakes, to quick breads and pies. When shopping for a sack of all-purpose flour, which one do you reach for: bleached or unbleached flour? And do you know what sets them apart?
The difference: Bleached and unbleached flour
All flours are bleached, but it is the process by which it happens that sets these two types of flour apart. Bleached flour is treated with chemical agents to speed up aging, while unbleached flour is bleached naturally as it ages.
Bleached flour uses bleaching agents (commonly benzoyl peroxide and chlorine gas, among others) to speed up the flour's aging process, resulting in a whiter, finer-grain flour with a softer texture. Bleaching softens the flour and gives finished baked goods a softer texture, more volume, and a brighter color than those made with unbleached flour. It is best for making cookies, pie crusts, quick breads, muffins, and pancakes.
Although treated with other chemicals, unbleached flour, with an off-white color a denser grain than bleached flour, is aged naturally after being milled. It also takes longer than bleached flour to produce, and because of this, it is usually more expensive. It is ideal base for things like yeast breads, cream puffs, éclairs, and pastries as its denser texture provides more structure in baked goods.
Can they be used interchangeably?
So what does that mean for your baking? While there may be differences in color, volume, and even smell of your baked goods from using one flour over the other, they will be slight. For baked goods, the overall basic outcome is the same with either flour. Your muffins will still rise, your cookies will still be delicious, and that layer cake will turn out just fine.