Call me crazy, but I don’t like drinking bleach. So, when I am in the baking aisle of my grocery store and see bleached flour, that’s an immediate pass. I’ll take my flour unbleached please! But that got me thinking: surely, there isn’t actual bleach in there. Big Flour holds a lot of sway but even they couldn’t get away with that. So what does it mean when it says that flour is “bleached.” And what is the difference between bleached and unbleached flour, anyway? Let’s get into it.
Bleached vs unbleached flour: What’s the difference?
After wheat is harvested and milled into flour, it doesn’t have that snow-white appearance that we immediately associate with it. Its color is tinged with the yellow from the wheat berries. This newly-made flour, if allowed to sit untouched and exposed to the air, will begin to oxidize and turn from yellow to white. Can you guess what another name for this process is? BLEACHING. So, if bleaching is something that occurs naturally in flour, why does Big Flour have to distinguish between the two on the bag?
The issue comes down to commerce’s greatest debate: time vs money. Way back when cavemen first said, “I want carbs!” and turned to wheat, the resulting flour was allowed to bleach naturally. This process can take anywhere from 1-2 months. Not only is that a lot of time, it also requires a significant amount of space and a significant amount of effort to prevent contamination as the flour sat there not being converted into chocolate chip cookies.
As the cavemen transformed into Regency Era sophisticates with a demanding sweet tooth, commercial flour production skyrocketed. Eventually—over a few centuries—this led to a lot of cutting corners to increase profits. So what did Big Flour turn to? CHEMICALS!
In 1906, artificial bleaching was permitted in the United States. The most common additives used in this process are nitrogen oxides, potassium bromate, chlorine dioxide, and benzoyl peroxide. The first thing I think about when I see the word “peroxide” is bleaching your hair with hydrogen peroxide in the bathroom sink in high school.
So, does bleached flour contain bleach?
Not really. But there are chemicals in bleached flour that make it whiter. And the Big Flour industry co-opted the word “bleached” to indicate when those chemicals were used as opposed to “unbleached” flour, which has none of those chemicals. The bottom line, however, is that all flour, if left alone for long enough, will “bleach” on its own accord. People are just too impatient for their cakes.
Are bleached flour and unbleached flour interchangeable?
When it comes to baking, yes. There is almost no difference at all in the final products made from bleached and unbleached flours, at least in my experience.
It is said that, because bleached flour is finer and softer than unbleached flour, it is the preferable option for making cookies, cakes, and, if you’re one of those fancy people who won’t just buy them pre-made, pie crusts. Alternatively, unbleached flour is more coarse, which means it is better suited to heartier bakes like breads and pastries.
My personal preference? Whatever flour gets the cookie into my mouth the fastest is the best. Like the Regency Era dandy boys before me, I demand my sweets!
