Photo from The Marmot's photostream
I have soaked beans overnight for years, thinking it both softened the beans thus reducing cooking time, and eliminating some of the gas produced in the intestines during digestion. Now, with my research into phytic acid and enzyme inhibitors found in legumes and grains, I have a better understanding of the process, and how to improve it.
Usually I soak beans overnight with at least 2 changes of water. Now with the information about neutralizing the antinutrients by soaking in an acid medium, I can do better. Sally Fallon (Nourishing Traditions) recommends adding 2 tablespoons of an acid medium per cup of grains or legumes to the soaking water. (I'll cover milled grains/flours in another post later.)
My preference for the acid medium will be Bragg's Raw Apple Cider Vinegar because the friendly bacteria in it will inhibit unwanted bacteria that could contaminate my soaking water. The next day, rinse well, and cook as you normally do. For years I have read Asian rice recipes where they soak rice overnight with a few changes of water. I thought it a cultural thing, not an improvement to the bioavailability of the nutrients in the food. So, yes, you can use just plain water, as I have done with my beans for years, but it will only break down a small portion of the phytic acid.
I happen to like the taste of a good vinegar, but if you do not, there are several other acid mediums you can use although the proportions should remain the same. You can use buttermilk, yogurt, kefir, whey, milk with fresh lemon juice to acidify it, cultured milk, regular vinegar, and lemon juice. There are probably other acids that will work, too, so feel free to experiment.
I cook a lot of whole grains like brown rice, bulgur, millet, quinoa, barley (both hulled and pearled), kamut, steel-cut oats and oat groats. You can be sure that my grains will be properly soaked from now on!
Update July 2010:
I finally (and reluctantly) have had to accept the idea that our systems are not designed to process grains, seeds, or beans after seeing the incredible improvement in my health and well-being without eating them for several months. Although I miss those items, I no longer eat any grains, seeds, or beans and only the occasional soaked nut meats. It still doesn't feel right (it's hard to eradicate what I was taught for so many years), but I cannot deny the improvement!