I have been reading a lot about the differences between bleached and unbleached flours and why bleached gives better baking results. It is my understanding that there are 2 types of commonly used bleaching agents: chlorine gas and benzoyl peroxide.  BP is for whitening only without improving baking properties. Chlorine gas which is used mainly in cake flour, helps “roughens up the surface” allowing flour to better distribute the fat, absorb more liquid and make it more acidic so the starch will set faster etc.  The question I have is: Which bleaching agent(s) are used for the commonly available American bleached AP flours (Pillsbury and Gold Medal) ?  In my readings it seemed to be clear that cake flour is chlorinated but it wasn’t clear how AP flour is bleached. If it’s just bleached with BP then would the baking properties necessarily be improved?

Thanks,
Jerry

Hi, Jerry, and welcome!

That was interesting to know that two types of bleach are used.  I didn’t know about the BP.

I feel confident that American bleached AP flour uses the chlorine method—this is because Rose gives the option of using cake flour or bleached AP flour in her recipes, as they perform with similarity, while advising against unbleached AP flour, as there will be significant differences in rise, texture, etc.

Glad you’ve joined us!

—ak

gfm8959 - 08 June 2012 05:42 PM

BP is for whitening only without improving baking properties.

I suspect that bleaching with bp must condition the flour somewhat- enough to allow butter to remain in suspension in an American-style butter cake batter.  There is a pretty big difference in the outcome of these cakes with bleached vs. unbleached AP.  Have you seen Rose’s series of articles, “The Power of Flour”?  You can search for them over on the blog.  Judging from the outcomes of cakes made with cake flour, bleached AP and unbleached AP, I’d venture a guess that bleached AP isn’t as roughed up as cake flour, but still can be used with acceptable results.

I have read the Power of Flour, which is what made me curious and learn more.  You’re probaby right about bleached AP which would be consistent with Rose’s results.
Thanks!