Flour – Bleached or Unbleached?

Flour is one of those pantry stables that most of us could not live without. I wrote an earlier Cooking Tip on all the different kinds of flours we have available to us. If you did not receive it and wish to read it, email me and I will forward it to you. For this current Cooking Tip, I want to focus on the difference between Bleached and Unbleached all-purpose flour. Cake flour is a different product, which I will address in an upcoming Tip.

There are two aspects to the debate on these flours. First, there are health concerns related to the use of chemicals added to flour. This is something that I leave to you to decide for yourself. The other aspect is how the flours act in our kitchens. That is what I will be discussing.

According to Harold McGee in On Food & Cooking, “freshly milled flour makes a weak gluten, a slack dough and a dense loaf.” These properties improve as the flour ages. Doughs made with aged flour will have more elasticity and structure.

Besides the structural differences, freshly milled flour tends to be yellowish in color. The aging process helps to change the color to white. Flour can be aged naturally but it takes 1-2 months. As millers began to understand this natural process, they began to use bleaching agents to chemically whiten the flour.

Some of the bleaching agents are banned in other countries. Although there may be limits on amounts, in the US, the FDA allows the use of many such chemicals. For a list, see this link.

The bleaching process does compromise some of the flour’s nutrients and results in a lower protein content, but these are often added back to the flour.

Another fact of which to be aware is that unbleached flour may also be treated with chemicals, usually potassium bromate, but it is treated with far less chemicals than bleached flour.

Bromated flour is flour which has been enriched with potassium bromate, a maturing agent which promotes gluten development in doughs. It is often used in bread production as it is said to make the bread stronger, more elastic and with bigger rises. It also bleaches the flour slightly. It is often used in low protein flours, which do not develop sufficient gluten. Some commercial bakers use this type of flour because it yields dependable results, and it makes a stronger, more elastic dough which can stand up to commercial baking tools. Ascorbic acid has replaced potassium bromate as a food additive in a number of areas as there is some concern that potassium bromate is a potential carcinogen. It has been banned in some countries and in California, the presence of potassium bromate requires a warning under Proposition 65. That regulation mandates warnings about the presence of chemicals that have been shown to cause cancer, birth defects or reproductive harm. The FDA lists it as an approved optional ingredient in bread.

In terms of how the flours act in our kitchen, the bleaching process produces a whiter and finer ground flour, which leads to baked goods that are softer in texture and brighter in color. Although not required, it is often recommended for cookies, pie crusts, quick breads, muffins & pancakes. Unbleached flour will have an off-white color and will not be as fine in texture. It is recommended when you want more structure such as yeast breads and pastries.

According to Cook’s Illustrated, “In baking tests, bleached flour was criticized for tasting flat or having ‘off’ flavors (texturally, the flours behaved the same). These characteristics, however, were much harder to detect in recipes with a high proportion of ingredients other than flour, such as cornbread or oatmeal cookies.” They did not find a discernable taste difference in savory applications such as thickening a sauce.

Cooking Light quoted Sharon Davis, of the Home Baking Association staff, “The difference between bleached and unbleached flour is basically indiscernible to the home baker. The bleaching process helps commercial bakers with consistency. Spread, texture, volume, and quality of grain must be exact each and every time but for the home baker, the only thing bleach has to offer is a whiter bread or cookie. “

They also did a testing among a panel of Cooking Light food editors and test kitchen professionals by testing four different recipes in a side-by-side comparison using bleached and unbleached flour. They tested sugar cookies, vanilla pound cake, buttermilk biscuits and brioche. The testers were unanimous in concluding that substituting unbleached flour did not compromise the result. In some cases, the tasters actually preferred the result with unbleached flour. They detected a slightly nutty, earthier flavor in the buttermilk biscuits made with unbleached flour as well as a slightly fluffier texture. They concluded that for the home baker, “bleached flour merely offers visual appeal – a whiter, brighter flour that only sometimes translates in the final baking product.”

In today’s stores, you can easily find unbleached flours. For some companies such as King Arthur Flour and Bob’s Red Mill, unbleached is the standard. King Arthur states that none of their flours contain any bleach, bromate, or artificial preservatives. Bob’s Red Mill says that their white flours are not bromated or bleached. Their white flour does contain malted barley flour, an ingredient they say has the same effect as bromating without adding chemicals. It does add a little extra sugar, which they say produces a stronger gluten reaction. Although King Arthur does not mention this, a look at the ingredient list shows that they also add malted barley flour. Bob’s Red Mill organic flour does not contain malted barley flour but King Arthur’s organic flour still lists this as an ingredient.

I tend to use King Arthur’s All Purpose flour and have not had a problem with it. What about you? What do you use? Have you noticed a difference in bleached vs unbleached flour? Why do you choose one over the other?

Let me know and as always —- Happy Baking!