Potasium bromate (KBr03) is a flour “improver” that strengthens dough and allows for greater oven spring and higher rising in the oven. Potassium bromate, commonly referred to as simply ‘bromate’ is a slow-acting oxidizer which contributes its functionality throughout the mixing, fermentation and proofing stages of the bake with important residual action during the earlier stages of baking. Azodicarbonamide (ADA), potassium and calcium iodate, and calcium peroxide are ‘rapid’-acting oxidizers, while ascorbic acid (vitamin-C) works at intermediate rates. However, unlike potasium-bromate, all of these compounds release their activity during the mixing and proofing stages, with little or very limited effect in the oven.

Bromate, when applied within the prescribed limits (15-30ppm), is completely neutralized during the bake, leaving no trace in the finished product. However, if too much is used, or the bread is not baked fully, or at high enough temperatures, then a residual amount can remain.

The primary concern regarding the use of bromates in baking is its demonstrated link to cancer in laboratory animals. It was first found to induce tumors in rats in 1982. However, since 1991, instead of banning bromate outright the US FDA, with somewhat limited success, has simply encouraged bakers to voluntarily stop using it in their baked products.

Bromates have been banned in numerous countries, including the United Kingdom in 1990 and Canada in 1994. In addition, in 1991, California declared bromate a carcinogen under the state’s Proposition 65. As such, baked goods sold in California that contain potassium-bromate must bear a store-level cancer warning if certain amount is used in their production.

The California Office of Environment Health Assessment’s “Intent to List” statement can be viewed HERE. This is an interesting document in that it highlights all of the research that lead to the inclusion of potassium-bromate on the Prop 65 listing.

While it wasn’t the case 10-15 years ago, today, all flour companies in the US produce flours that are bromate free. If you are a baker who is currently using bromated flours and are considering the switch to flours that contain no bromate then you will have to make some slight adjustments to your mixing process.

The most common adjustment that most bakers find they need to make are slightly longer mixing times. Bromate, being an oxidizer, rapidly strengthens the dough in the mixer bowl thus reducing mixing times (one of it ‘benefits’ in a high-throughput bakery: less mixing time means more dough can be produced). Thus doughs made from flours without bromate will require slightly more mixing to achieve the same strength. As you do not want to increase the final temperature of the dough through this additional mix (which is usually done at high speed) you must lower your initial water temperature. Those two changes, along with some extra vigilance during this transition, should be all that is required by you or your bakers during this transition.

Some bakers find that they do not have as much fermentation tolerance using un-bromated flours. There are two solutions for this. One is to use preferments in your dough. This increases the acidity of your dough giving it additional tolerance for longer proof times and overnight retarding. If this doesn’t fit your production requirements then you can consider using ascorbic acid (Vitamin C). Ascorbic acid is a slow to intermediate acting oxidizer. This means you will not get much action in the mixer bowl but your doughs will have increased tolerance to overnight retarding.

Given consumer’s increased desire to consume products with as clean an ingredient label as possible, along with a growing awareness of what is in their foods, bakers would do well to consider a switch to a promate free baking process. You products will have cleaner nutritional labels, be healthier for your customers, and you will be providing your bakers with a safer working environment