Bleached or Unbleached Flour – Which Is Better?

Flour is made from wheat and it may be bleached with bleaching chemicals or exposure to oxygen. Bleached flour is a better option for baking.

There are several types of flour on the market, and it can be hard to figure out which one is best. The types of wheat used and whether or not the flour is bleached are just a few of the factors that can separate the various types of flour from each other. To add a layer of complexity, unbleached flour is technically still bleached: It’s just bleached in a more natural way. The process that bleached flour goes through makes it generally easier to use when baking. 

Flour is made from wheat, which includes six categories:

• Durum
• Hard red spring
• Hard red winter
• Hard white winter
• Soft white spring
• Soft white winter

Within these six classes, there are over 30,000 varieties of wheat. Some types of wheat are better for certain types of baking products than others. For example, hard wheats are better for bread, and soft wheats are better for pastries. 

After harvesting, the wheat goes through a six-week process called sweating. This process improves the milling quality of the grain and reduces moisture. Next, quality control removes things like sticks and stones: anything that doesn’t belong with the grain.

The next step is tempering the grain. In this step, chlorinated water is added to the grain to stop bacterial or microbial growth and to help separate the grains. U.S. factories typically temper the wheat for about six hours, while factories in Europe temper their wheat for 24–48 hours.

Next, it’s time to mill the wheat. Milling involves crushing and grinding the grain into small pieces, often using stones, hammers, or rollers. The more the grain is milled, the smaller the pieces will be, and the more flour you’ll get. In the case of standard white flour, any leftover bran is sifted out, but in the case of whole wheat flour, it’s left in.

The bleaching process occurs after the flour is freshly milled. There are two ways to bleach flour: with bleaching chemicals or exposure to oxygen. It takes several months to bleach flour with oxygen, and the final product is referred to as “unbleached flour.” 

On the other hand, bleaching flour with bleaching agents takes only a couple of days. In 1906, the Pure Food and Drug Act put together a list of approved bleaching agents, though it’s been adjusted over time. Currently approved options include:

• Benzoyl peroxide
• Chlorine dioxide
• Nitrogen peroxide

Flour is not naturally white. Wheat naturally contains molecules called carotenoids. These give the wheat its typical golden color. They are also responsible for making carrots orange. Historically, people haven’t been a fan of the golden color, though: They want their flour white. 

When flour is bleached, the bleaching agent breaks apart the bonds within the carotenoid molecules, turning the flour white. Chemical bleaching takes a lot less time than natural bleaching, too, allowing the bleach to hit store shelves faster and at a lower cost.

Chemically bleaching flour has more benefits than just improving efficiency and turning the flour a nice shade of white, though. Bleaching the flour also:

• Creates a finer grain
• Extends the flour’s shelf life

Adding these bleaching agents to the flour also oxidizes the flour’s proteins. When this happens, the proteins are modified, leading to the development of gluten.

As a result, the dough becomes less sticky, and it is easier to handle. This also creates a better texture and volume for baked goods.

Generally speaking, the benefits offered by the bleaching agents make bleached flour more user-friendly than unbleached flour. Bleached flour makes baked goods more consistent. They also have a better texture and rise better.

Unbleached flour is good for creating a very compact and dense loaf of bread, but that’s typically its only advantage.

When you walk down the baking aisle in your local grocery store, you may be confronted with several different types of flour. Each type of flour has specific characteristics that make it best for specific types of baking projects.

All-purpose flour

All-purpose flour is your basic, everyday flour. It’s made from a blend of hard wheat and soft wheat. All-purpose flour is incredibly versatile and can be used in most types of baking.

Bread flour

As the name suggests, bread flour is the ideal flour for making bread and most other yeast doughs. It’s made from hard wheat and, as a result, has a very high gluten content. It is an off-white color.

Cake flour

Cake flour is almost the opposite of bread flour. It’s made from soft wheat and has a very low gluten content. Making cake flour requires a specific process that allows the flour to hold liquid and sugar, making it the ideal flour for delicate products like angel food cake or a souffle.

High-gluten flour

High-gluten flour, like bread flour, is made with hard wheat, though it has more gluten and less starch than bread flour. It creates a dough that can stretch without tearing, which is ideal for crusty, crumbly bread. In a pinch, though, bread flour is the best substitute for high-gluten flour.

Pastry flour

Pastry flour is similar to cake flour but has a higher protein content. All-purpose flour is generally a fine substitute for pastry flour, or you can make your own pastry flour with 50% all-purpose flour and 50% cake flour.

Self-rising flour

Self-rising flour can be made from either all-purpose flour or pastry flour, with salt and baking powder added. It’s convenient but should only be used in recipes that call for it, as the amount of salt and baking soda you need will vary.

Whole-wheat flour

Whole-wheat flour is made from hulled wheat: that is, wheat that has the grain hull stripped away but which still has its bran and endosperm content. As a result, it contains more fiber and nutrients. Whole-wheat flour can be used instead of all-purpose flour in some recipes, though it often creates a denser, heavier texture.

Bleached flour is made using certain chemical agents. This typically makes bleached flour a better option for baking. 

Unbleached flour, in contrast, is whitened with oxygen exposure and often doesn’t work as well if you are baking bread or pastries.