From the comments section here: a recipe for fermenting oatmeal using miso.
South River Porridge
1 cup rolled oats
2 cups water
2 teaspoons light miso (see note below)
Cook oatmeal in the evening 5-10 min., or until water is absorbed. (Do not use salt in the cooking.) Let oatmeal cool down to body temperature and then stir miso thoroughly into the warm cereal. Cover and let sit overnight at room temperature (about 70°). Reheat in the morning (without boiling) and serve.
Without imparting a noticeable taste of its own, the enzymatic power of the miso will liquefy the cereal, unlocking its essential nutrition, creating a wholesome sweet taste as it ferments overnight.
Other whole, rolled, cracked, or ground, cereal grains may be used, although cooking times will vary as necessary. Many pre-industrialized peoples fermented their grains to gain the most energy and nutritional strength from them.
Note: For this recipe it is necessary to use an unpasteurized light miso, rich in amylase enzymes. Choose South River Chick Pea, Sweet Tasting Brown Rice, Azuki Bean, or Sweet White Miso.
Creamy Oat Milk
Follow the same recipe above using 3 cups of water to 1 cup rolled oats. In the morning use a blender to transform the liquid porridge into a smooth milk. Strain if desired, heat and serve. Delicious with a touch of ginger!
Various sources say that soaking alone is not enough to reduce phytates in oatmeal. The Nourishing Home recommends adding some other grains with higher phytase content.
The one exception to the above soaking rule is oats. Oats contain a large amount of hard-to-digest phytates and other anti-nutrients. Unfortunately oats are so low in phytase (the enzyme that helps to break down phytates), that soaking them in warm water mixed with an acid medium is not enough to adequately break down the large amount of anti-nutrients that naturally occur.
However, with the help of some additional phytase added to the soak (in the form of rolled rye flakes, or if you’re GF use ground buckwheat groats – both are high in phytase) – along with a full 24-hour soak time – a fairly decent amount of the anti-nutrients can be removed, making the oats more digestible and nutritionally sound.
Here is her recipe for oatmeal:
I tried this recipe for fermented oatmeal from thekitchn.com: Soak 1 cup oatmeal in 1 cup water with 2 tbsp yogurt overnight for 8-24 hours.
With an overnight soak, the taste was about what you’d expect from oatmeal and yogurt, not exceptionally earth-shattering.
I liked it better the second time I tried it, with a 24 hour soak using kefir. The flavor wasn’t sour at all, but a little extra nutty and complex.
Nora refused to eat it until my mom mixed it with some full-fat, plain yogurt. I might want to try coconut milk sometime, just to change things up for both her and me.