Monday, September 22, 2014

To Soak or Not to Soak

Beans have become a mainstay of my plant-based diet.  Every Sunday I make a big batch that I can use as a base recipe all week long.  Black beans, chickpeas, adzuki, cannelloni, fava...I have no favorite, I love them all.  Beans are nutritional powerhouses, rich in protein and vitamins and flavor but I used to think they were a nuisance to make.  It wasn't until I got my InstantPot, a combo pressure cooker, that I started making beans in batches.  Cooking beans without pressure seemed to take forever, or I would just resort to canned beans.  I tried presoaking beans overnight or quick-soaking, which does reduce cooking time but only by about 25%.  With pressure, however, it takes the cooking time of your average bean from 1-2 hours down to 20-30 minutes.
Recently I began to wonder...if pressure cooking is so efficient at cooking beans, is soaking is really necessary at all?  Searching the interwebs, I see there are many debates on this topic, and the science does not seem settled (whether it's healthier to soak or not, nutritionally) either.
On the pro-soak-side, soaking is thought to remove water soluble starch sugars that can block digestion. Some argue that these compounds called phytates are also what cause flatulence.  So it would seem this is a good thing.
"The soaking of black beans in water has always found fairly widespread support in food science research as a way of improving overall black bean benefits."
That is according to the site, World Healthiest Foods, which seems to provide a fairly reliable source of nutrition information.  So removing phytates, which block digestion of other nutrients is good.  But I found other evidence on the other side discussing how we are leaching more nutrients by soaking. Food science writer Harold S. McGee wrote in a book called On Food and Cooking:
"...during soaking many nutrients leach out of the beans. Apparently heat breaks down cell membranes within the beans, and increases the solubility of water-soluble nutrients, such as calcium, magnesium, thiamine, riboflavin, and niacin. As a result, soaking tends to leach somewhat more of the nutrients out of the beans than do slow soaking methods."
pre-soaked pressure cooked black beans
So we should keep the soaking the liquid if we want to maximize all the nutrients. Ok, but I thought we should discard the soaking liquid because it has those digestion blocking phytates.  Hmph.  The more I looked for answers, the more questions they seemed to raise.  Then there is the all important question: which tastes better?

not soaked pressure cooked black beans
On this one, I can say I think I found a winner.  I used to always pre-soak my beans overnight.  Now I don't bother if I'm going to pressure cook them.  I use a small piece of kombu to help neutralize the phytates, a pinch of salt for flavor and I also found that they definitely taste a lot better.  I was amazed at the difference and I was skeptical even after reading this thorough taste test.  In my own kitchen experiment, I concur that the texture and flavor of the non-soaked black beans is superior to that of soaked.
Do you soak your beans?

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