This week I learned a few important things about foraging for acorns, the nuts of oak trees.
First of all, if you are going to bother picking up all those acorns, shell them and start processing them immediately. They may not appear to have nut weevils in them, but somehow they magically appear after the acorns sit on your kitchen counter for a week! No, I didn’t take photos… you’ll just have to trust me on this one.
Second: you can’t just be a slacker about leaching the tannins! Acorns, like the trees they fall from, are high in tannins which make them singularly unpleasant to eat straight from the tree. Some species are higher in tannins than others; the red and black family of oaks (which have leaves with pointed lobes) tend to be higher whereas the white oak family (with rounded leaf lobes) tend to be lower. Luckily, tannins are water soluble so they can be removed by either a “hot” leaching method, or a “cold” leaching method.
Hot leaching requires putting the shelled acorns through multiple changes of boiling water. Once the poured-off water is no longer colored, you can start sampling the acorns for edibility, and continue changing the water as needed until the flavor is ideal.
Cold leaching simulates the Native American approach of putting the acorns in a bag in a running stream, which allows the tannins to be washed out over a longer period.
“Lazy leaching”, which is what I tried to do, is apparently Not a Thing. I put the shelled acorns in a bowl, filled it with cold water from the sink, and changed out the water every couple of hours … or whenever it occurred to me. Which might not have been all that often.
After a day of this, the water didn’t seem to be brown at all, but the acorns still were mouth-puckering bitter. (Eating an unprocessed – or underprocessed – acorn is only slightly less awful than eating an unripe persimmon.)
Another day of changing the water out infrequently … another awful experience sampling an acorn.
Wash, rinse, repeat. After the third day, the acorns looked very waterlogged, and I abandoned the attempt.
Maybe for cold leaching, the acorns need to be ground first. At least once source I read mentioned this, but never explained why. And I have this terrible habit of skipping steps if I don’t know what they do. Oops?
Another possibility is that the water wasn’t cold enough, or that the water changes didn’t happen frequently enough.
Last but not least, perhaps there are some trees whose acorns are simply too bitter to even bother.
Hopefully, I can find more fresh acorns so I can try again!