Bromated flour is flour which has been enriched with potassium bromate, a maturing agent which promotes gluten development in doughs. Some commercial bakers use bromated flour because it yields dependable results, and it makes stronger, more elastic dough which can stand up to bread hooks and other commercial baking tools. Home bakers may choose to use it for much the same reason, when they can obtain bromated flour. Ascorbic acid has replaced potassium bromate as a food additive in a number of areas.

Potassium bromate is classified as a potential carcinogen, meaning that it may be harmful when consumed. In theory, the substance is supposed to bake out of bread dough as it cooks, but if a residue remains behind in the bread, it could be harmful in the long term. A careful balance is required of manufacturers, since they must add enough of the substance to bromated flour to make it perform as expected while not adding too much. Many flour producers have switched to ascorbic acid, which has similar properties without the potential health risk.

In some countries, bromated flour has actually been banned out of concerns about health risks. In the United States, bromated flour is legal, although state by state labeling laws may dictate that a flour producer clearly label flours which contain potassium bromate. Some organizations such as the Center for Science in the Public Interest have lobbied the Food and Drug Administration to ban potassium bromate as a food additive in the United States. Many bakeries and flour mills pride themselves on using unbromated flour, and market their products accordingly.

Typically, bromated flour is used in bread production. Adding potassium bromate makes the bread stronger and more elastic, and also promotes big rises of bread. The resulting bread tends to be strong and springy, well suited to commercial production especially. The substance also bleaches the flour slightly, creating the creamy white color which most people associate with flour. It tends to be used in low protein flours more commonly, since these flours do not develop enough gluten on their own.

Consumers who are concerned about using bromated flour can seek out flours which do not contain potassium bromate. When baking bread, a high gluten flour is very useful, and many flour mills formulate products specifically for bread production which will be clearly labeled as “bread flour.” A number of options including whole wheat and white unbleached are available.