The Difference Between Bleached and Unbleached Flour
All-purpose flour is all-purpose flour, right? Well, yes and no. Stroll down the baking aisle at your supermarket and take a closer look at the those sacks of flour and you'll see that this pantry staple actually comes in two forms: bleached and unbleached.
If you've spent your entire life cooking and baking without realizing that there are different types of all-purpose flour, don't worry! Your secret is safe with us. For the most part, you can use them interchangeably with good results. Both flours have a medium level of protein, which makes either of them ideal for baking cakes, cookies, and pie crusts, thickening sauces and gravies, breading cutlets, and all of the usual suspects.
So what's the difference between the two? True to its name, bleached flour is mixed with chemical additives (chlorine dioxide and benzoyl peroxide), which give it the bright white color that we're all familiar with. These additives also assist in aging the flour, which helps it produce lighter and more tender baked goods.
Unbleached flour is aged naturally (with no or fewer chemical additives) by being exposed to oxygen over a longer period of time. It has a slightly darker color than bleached flour and has a texture that is a bit more dense. Because it takes more time to age the flour naturally, it is usually more expensive than bleached flour. Bleaching flour the natural way also preserves more of the nutrients found in wheat.
Unless you are making a vanilla cake that needs to look very white in appearance or a cake that needs to be exceptionally tender (like an angel food cake), you can use all-purpose bleached or unbleached flour for all of your cooking and baking needs, unless the recipe calls for a specialty flour. (Just as you did before you learned about this information!)