1. First off, I gathered acorns. As you can see, acorns of the Chestnut Oak are rather big.
2. I attempted to dry them in the oven.
Let me tell you something about drying acorns for flour. Native Americans used to do it so that they could store the acorns for awhile before turning them to flour, and the acorns would not spend the interim time rotting. The exceedingly helpful Ramshackle Solid blog describes having the acorns of Live Oaks, when dried, open themselves. The blogger does add the caveat that this may just be Live Oaks.
If you, friends, are ever considering making flour from the acorns of a Chestnut Oak, and the idea of first drying the acorns in an oven flits across your mind: don't do it. It is like feeding gremlins after midnight. It makes them stronger and meaner.
(By which I mean that the nuts will go from having pale, moist kernels that easily pop out of their shells to brownish kernels that stick to the insides of the shells.)
3. I salvaged the best-looking kernels and gave them a brief chopping. This isn't all of them.
4. I put them in my marvelous blender and added water. Note how I appear to have stuffed my blender with wood chips. This also roughly reflects the interesting - by no means bad, but not especially appetizing - smell of the acorn kernels.
6. I lined a colander with cheesecloth and rinsed the blender out into it.
7. This is the part where one rinses out the tannins. Tannic acid can be used to tan leather, and is toxic to humans in large quantities, but merely bitter in small ones (there are tannins in tea). It's also water soluble. One just has to rinse until the acorn flour tastes mild rather than bitter.
This was the first time I had tasted any part of this process, and I was a little wary. Hence the expression.
8. The finer-ground pieces became mild quickly, while the larger chunks were still bitter. I dried the acorn mush, then repeated the blender/rinse process. This is the flour as it now stands, drying.
(The chunk-like parts are clumps. It's actually fairly fine now.)
I was particularly surprised with how similar the acorns were to peanuts inside - the kernels were split in half, with no membrane or shell in between (as in walnuts), and had the little nub at the bottom that peanuts have. So I learned something!
Of course, it isn't over, as I still have to bake . . . something.