MFC: You must throw away the soaking water. This is the only way to prevent the
tummy music.
AB: Tummy music? What the heck is tummy mu ... oh.
Oh sure, blame those poor defenseless little beans for your emission control problems. Well, whether you like it or not, the true enemy lies within.
[voice over] Over the lips, past the gums, look out stomach here it comes. Now, once your latest nosh is mashed to mush in the stomach and moves off to that molecular chop-shop the small intestine. There, chemical sledge hammers called enzymes further dismantle your meal. It is then absorbed by the intestinal wall and becomes body fuel.
Now unfortunately, beans contain large numbers of humungous sugars called oligosaccharide. Alas, the human tool kit lacks an enzyme capable of cracking such a colossus. So, they skip the absorption step and move off to the large intestines intact.
There, a host of voracious bacteria lay in wait for a passing meal. None of this would be particularly compelling but for one fact. You see, when they eat these bacteria get really bad ...
... gas. But there are solutions. For one thing, chew thoroughly. I mean, the more the beans are broken down, the better. Now, there are cooks out there that claim the Mexican herb, epazote, preserves gas, but science has yet to bear that one out.
What we do know for sure is that certain kinds of mold produce an enzyme called, alphagalactosidase, which can digest oligosaccharides. So, you can either eat this [piece of moldy bread] with your beans, or you can sprinkle on a few drops of one the commercial applications containing the same enzyme. Either way, you'll be able to digest the whole thing. Temporarily.
So as for the soaking liquid, sure a few of the oligosaccharides have leached out into it. But you know what? So have a few vitamins and a good bit of flavor. So, regardless of what he says, I say don't throw the baby out with the bath water.