When I initially filmed and posted this video a decade ago, I had learned this phytate-disabling soaking technique from a famed cookbook called, Nourishing Traditions. This cookbook was based upon research into indigenous food preparation and diet by healthy tribes, detailed in the book, Nutrition and Physical Degeneration, originally published in 1939 by Dr. Weston A. Price.
The issue with phytic acid is summed up in this article by the authors of that cookbook, Sally Fallon and Mary G. Enig:
“Animals that nourish themselves primarily on grain and other plant matter have as many as four stomachs. Their intestines are longer, as is the entire digestion transit time. Man, on the other hand, has but one stomach and a much shorter intestine compared to herbivorous animals. These features of his anatomy allow him to pass animal products before they putrefy in the gut but make him less well adapted to a diet high in grains—unless, of course, he prepares them properly. When grains are properly prepared through soaking, sprouting or sour leavening, the friendly bacteria of the microscopic world do some of our digesting for us in a container, just as these same lactobacilli do their work in the first and second stomachs of the herbivores.
…Our ancestors, and virtually all pre-industrialized peoples, soaked or fermented their grains before making them into porridge, breads, cakes and casseroles.”
Well, a lot more research and experimentation into phytates (and other anti-nutrients found in plants) has been done since then and we now know it is not so simple as just soaking grains in an acidulated medium overnight.
This lengthy article by Ramiel Nagel was compiled over many years and pulls all the information together into one place. I’ve cherry-picked information relating to the top questions/concerns I hear from readers, but I do encourage you to read the entire article. It contains extensive information on every aspect of soaking/sprouting to disable phytates, including detailed indigenous food preparation techniques.
Phytic acid is also called inositol hexaphosphate (IP6) and it functions as the main storage form of phosphorus within the plant. A key point to understand in this discussion is that the phytates in food are disabled by an enzyme called phytase. And each food (tuber, nut, seed, bean, grain etc) that contains phytic acid (phytates) also contains phytase. BUT you have to unlock or activate the phytase before it can do it’s job. Soaking in an acidulated medium, as per my video, activates phytase – which then reduces phytic acid. Sounds good so far, right?
The problem is that it either doesn’t activate it enough, or the food itself doesn’t contain much phytase enzyme, “For example, corn, millet, oats and brown rice do not contain sufficient phytase to eliminate all the phytic acid they contain.”
Then commercial food prep can further complicate things. In the case of oats (oatmeal, oat flour, etc) vendors purposely heat oats to stop them from going rancid, but this also destroys the phytase