Fava bean flour is one of the worst things you can possibly do to bread. It
acts as a bleaching/oxidizing agent and will do irreparable damage to the
color of your bread's crumb and taste.
Back in the aftermath of WW2, french wheat was consistently hypodiastatic
every two years out of three. This means that the color of the finished
bread's crust would be pale and ugly. Millers began adding fava bean flour
to add more enzymes to correct this problem. It also had the unintended
consequence of bleaching and ruining the bread.
The only reasons that this practice is continued today is tradition and the
myth and misconception that customers like really white, insipid bread.
You're better off making bread without additives, honestly.
The french bakers who use fava bean flour also mix their bread for far too
long and because of the oxidizing this causes must almost omit the bulk
fermentation. They do end up with loftier loaves. But they sacrifice aroma,
taste, and nutrition.
If you want an amazing explaination of this (and other) additives, check
out "The Taste of Bread" by Prof. Calvel. It's a very technical book, but
I've found it to be one of the best books on the making of good bread.
Cheers,
Pete Solis
Woodstar Cafe