We all know what flour is and most of us have been using all-purpose flour all our lives. It’s the easiest and most readily available kind of flour in any market. We use it to make desserts, bread, pancakes, waffles and we even use it to make roux.

So you’re walking down the grocery aisle to pick your usual all-purpose flour and then in the corner of your eye you see and bag that says, “Unbleached All-Purpose Flour”. Imagine the camera zooming into your face and you saying, “What is this?”

What is the difference between bleached and unbleached flour?

Bleached flour and unbleached flour are both flours but let us tell you this. Not all flours were made equal. In the earlier decades when processing wheat flour became bigger than it already was, consumers decided that they didn’t want the yellowish flour anymore. Consumers said that they wanted whiter flour and they want it now.

You see, flour has a yellowish pigment in it called carotenoid – the same kind of molecule that gives carrots its orange color. When flour is processed, the carotenoids in the flour remain but eventually whitens through time when exposed to oxygen. Given the demand, scientists were able to come up with a way to bleach flour instantaneously – 2 days to be more exact while naturally bleached flour takes up to a month to process. This was the birth of bleached flour.

Bleach flour is flour bleached with safe chemicals like nitrogen peroxide, chlorine gas, chlorine dioxide, nitrogen dioxide and benzoyl peroxide. These chemicals are added to the freshly milled flour and it takes up to 48 hours for the pigments to get destroyed, et voila! Bleached flour.  Bleached flour turns into a lighter flour with lower protein levels, finer and keeps longer in your pantry. Bleached flour is more economical because it takes a shorter time to process. Bleached flour results in a softer product.

Unbleached flour on the other hand is flour that did not undergo the chemical bleaching process. Once the flour is milled, it is kept on the shelves longer for the color to bleach over time, naturally. Again, flour naturally turns white over time when it is exposed to oxygen. This takes longer to make, making it more expensive. Unbleached flour is more protein-heavy compared to bleached flour and it creates a stronger gluten network compared to bleached flour.  Unbleached flour results in a tougher and denser product.

The difference in nutrition and health impact

The difference in nutrition isn’t too far apart from each other. However, if your palate is sensitive, you will notice the difference in taste.

Both flours have roughly the same number of calories, fat, fiber and carbohydrates per serving.  Unbleached flour will have a slightly higher percentage of Vitamin E because the bleaching process will destroy that aspect in bleached flour. The difference isn’t too great.

Unbleached flour will have more vitamins and minerals such as fiber, manganese, copper, and antioxidants while both are still packed with vitamin B, folate, niacin, thiamine and vitamin B6.

What purpose does flour serve in our baking?

The backbone of baking is flour, no doubt. Sure fat, water, and sugar have a lot to do with it but without flour, what is bread?

Flour is made out of proteins, starch, sugars and more. The two stars of flour are starch and protein because these two are the ones that create the bread, that tangible texture that is the objective of baking in the first place.

What makes bread, bread is the network of gluten formed by starch and protein mixed with water or fat. When this network is formed and introduced to heat, these tiny air bubbles will expand and crust up.

Flour is the foundation.

When should I use bleached flour vs. unbleached flour?

Bleached flour should be used for baked goods that don’t require heaviness. Bleached flour is perfect for making cookies, pancakes, waffles, pies, quick breads and muffins. Bleached flour results in a softer texture, more volume, and lighter colored finished product compared to unbleached flour.

Unbleached flour is best for baked goods that you need a stronger structure for like sourdough bread, rye, other yeast breads, cream puffs, and other pastries.