Beans: to soak or not.

(Repost)

Man, I hate when there’s no clear answer to a cooking question.

The question is whether or not it makes sense to soak dried beans before cooking. You have three options: Soak overnight in cold water (they’re actually fully soaked after about four hours, but can stay in the water for up to eight hours); soak quickly in one hour by starting with boiling water; or don’t soak and increase your cooking time and cooking liquid.
Here are the arguments I’ve found for and against soaking:

• Soaking frees up minerals and vitamins in the beans. Beans contain a chemical called phytic acid, which “can form complexes with some minerals and make them insoluble and thereby indigestible,” a process known as chelation. Some phytic acid is destroyed in cooking, but more is removed (an extra 15.4% up front, according to the American Chemical Society) if you soak overnight before cooking.
• Soaking cleans the beans. Got that from Miss Vickie’s, the best site around for pressure-cooking tips. She says there’s a lot of nasty stuff on the outside of dried beans. I think that a really good rinse should take care of that nasty stuff, and besides, letting the beans sit in water that has absorbed undesirable compounds sounds like a bad idea. But what do I know.
• Soaking reduces cooking times. It does – by maybe a half an hour. Doesn’t bother me. Might affect people who have office jobs, although I’m guessing you’re still not making two-hour beans on a Tuesday night.
• Soaking cuts down on “ze tummy music.” I’m pretty sure this is bullshit, but then again, everything gives me ze tummy music, so how the hell would I notice?
• Soaking means softer beans. I know this is bullshit, because I’ve tried it both ways, and soaking did not help the texture of the cooked beans one iota. You know what helped? Cooking them longer.

Arguments against soaking beans:

• Soaking leaches out flavor. Well, you have my attention there. Alton Brown has suggested soaking and then using some of the soaking liquid in cooking, although in this season’s red beans and rice episode (a good recipe, BTW), he dispensed with soaking entirely. I have made beans both ways, but I’m usually putting so much other stuff in the pot that I would never notice a 10% flavor loss through soaking. My beans tend to taste like other things, such as bacon.
• Soaking removes the phytic acid. Yeah, how about that: Phytic acid is an antioxidant. I found a few studies discussing phytic acid’s antioxidant properties, although none seem to argue strongly in its favor. It has been mentioned as a potential anticancer compound, and it definitely plays a role in preventing bean spoilage.
• Soaking leaches out nutrients. So perhaps we’re even – soaking takes out nutrients but gets the phosphate out of the phytic acid so that the remaining nutrients are more accessible; not soaking leaves the phytic acid but the beans start with a higher nutrient content. I have no idea how that nets out.
• Soaking is not traditional. I know it’s just a forum post, but this caught my eye: You’re probably all bored to death with my saying this, but I have lived in Mexico for nearly 26 years. I do not know a single Mexican cook who soaks beans. Naturally, YMMV. Rick Bayless, who knows a thing or two about Mexican cuisine, also advises against soaking. Not a nutritional argument, of course.

Usually I can at least offer an opinion based on a preponderance of evidence, perhaps mixed with personal experience or observation, but on this one, I just don’t know. You might have a tradeoff between tradition and nutrition, or between convenience and flavor.

I can only tell you what I do, or what I don’t do: I’ve stopped soaking beans. I never found a cooking benefit, and I was unaware of a nutritional question until shortly before I started writing this post. I did find something interesting in, of all places, Wikipedia – and, oddly enough, it comes from a bona fide academic source:

Probiotic lactobacilli, and other species of the endogenous digestive microflora as well, are an important source of the enzyme phytase which catalyses the release of phosphate from phytate and hydrolyses the complexes formed by phytate and metal ions or other cations, rendering them more soluble ultimately improving and facilitating their intestinal absorption.

That indicates to me that popping a couple of L. acidophilus pills before chowing down on some (unsoaked-before-cooking) beans might help you get the best of both worlds. But beyond that, I’m as confused as ever.