Please catch up on all the soaking grains research for the scoop on phytates, phytic acid, phytase and more!
I’ve been looking for another “real scientist” to balance the Great Debate between Sally Fallon and my Australian PhD contact. Imagine my joy when I stumbled across Stephan Guyenet, Ph.D. a Senior fellow at the University of Washington, Seattle, in the Department of Medicine’s Division of Metabolism, Endocrinology and Nutrition. He blogs about his studies of “time-tested strategies for achieving and maintaining health and well-being” at Whole Health Source.
Be still my beating heart! Not only does Stephan know what phytates, phytic acid and phytase are, but he was willing to share his research with me so I could dig through the journal articles myself. In his post A New Way to Soak Brown Rice, he details the 96% effective method that I’ll share with you today.
New research from China in 2008 explored various methods of reducing phytic acid in brown rice. The trouble with brown rice is that although it is lower in phytic acid than other grains, it has a dismally low level of phytase, so soaking, even in an acidic medium, isn’t going to do much to impact the phytic acid. The authors of the study were able to reproduce some of the effects of sourdough fermentation on phytic acid in wheat by using a unique method for soaking their brown rice.
Termed accelerated fermentation, the process increases both natural phytase activity in the grain, and a sort of lactic acid fermentation, which also creates further phytase activity. I now have a little jar of soaked rice water in my refrigerator as a “starter” for my rice.
SWN is soaking in water, and SWA is a soak in an acidic medium like Nourishing Traditions often recommends. Both are for a whole day. You can see in the chart above that phytic acid is reduced by less than half with both soaking methods, but almost down to nothing with the accelarated fermentation.
Here’s how it works:
- Soak brown rice in dechlorinated water for 24 hours at room temperature without changing the water. Reserve 10% of the soaking liquid (should keep for a long time in the fridge). Discard the rest of the soaking liquid; cook the rice in fresh water. UPDATE: I reduce the amount of water added at this point. For example, if I have 1 cup rice and 2 cups water to soak, I pour off the water (reserving some) and add about 1 1/2 or 1 3/4 cup fresh water. You could be really precise and measure what you pour off, then add the same amount fresh to make up for what the rice has already absorbed. This makes a big difference in cooking nice rice! Don’t forget the rule of rice cooking – no peeking under the lid once you reduce to a simmer!
- The next time you make brown rice, use the same procedure as above, but add the soaking liquid you reserved from the last batch to the rest of the soaking water.
- Repeat the cycle. After three times, 96% or more of the phytic acid should be degraded at 24 hours.
Neutralizing and reducing that percentage of phytic acid is unheard of with other methods and grains. Even sourdough only decreases phytates by 64%. The modified fermentation acidifies the water and continues to keep the pH stable and even lowers it, whereas soaking in slightly acidic water ends up moving closer to a neutral (7) pH as time passes.
The goal of all this soaking and fermenting is supposed to be to reduce the levels of phytic acid in your grains so that minerals are more bioavailable and easy to assimilate into your system. After taking care to soak brown rice the third time with a bit of old starter water, the phytic acid is almost gone completely.
The sad news is that at the end of this research journal entry, the researchers found that zinc, the mineral in question for their study, was almost no more well-absorbed after the accelerated fermentation than it was before. They concluded that more study is needed; I concur and am left wondering if the work involved in soaking is worth it. There are other positive impacts beyond just phytic acid reduction, luckily.
Another way to reduce phytic acid in rice: germinated brown rice.
Source: Effects of soaking, germination and fermentation on phytic acid, total
and in vitro soluble zinc in brown rice by Jianfen Liang, Bei-Zhong Han, M.J. Robert Nout, Robert J. Hamer. a College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China