Yesterday I gathered acorns for my wild edible plants class. I’ve never really thought of an acorn as a nut or even something you could eat, and on occasion I’ve even heard that they are poisonous. That is very much not the case.
The guy who wrote my wild edible plants book, Samuel Thayer, is a big fan of acorns; or maybe he isn’t, but he dedicated fifty pages in one of his books to how to harvest and prepare acorns. Apparently, some Californian Indian tribes depended on acorns for a lot of their food, which makes sense, because some of the best varieties of acorns grow specifically in California.
The reason I heard they were poisonous is because if you ate about thirteen and a half trillion acorns at once, you would probably die. They have a lot of tannin in them. In low amounts, tannin is fine for the average human to consume, as almost everything has some tannin in it; apples, green tea, persimmons, for instance. The reason acorns are feared for their tannin content is because it is higher than levels of tannin in other foods.
You can leach the acorns, and then they are fine to eat.
I wanted to find out what those Californian Indians were so very enthralled with. We went out and gathered maybe a pound, possibly less, of red oak acorns. It wasn’t very much, but they were kind of hard for us to find surprisingly. Anyway, for those of you who haven’t read about eating acorns, weevils like to lay eggs in acorns, and their maggot offspring grow up in the acorn, feeding off the nut inside. Later in their development, they eat a hole through the shell of the acorn large enough for them to crawl out and turn into weevils.
Obviously you don’t want these acorns, but we did pick up a few. How to get rid of them? Well, the acorns the weevil larvae have eaten are light, so, in theory, if you were to fill a bucket with water and dump all your acorns in it, the bad ones would float. So that’s what I did, and it eliminated most of the bad acorns, of which there were about six.
I then proceeded to crack and shell the acorns. The author of my book said that this is easier to do when the acorns are slightly warm, so I put them in the oven at 200ºF for about 4 minutes. Then I went outside, laid a towel on the garage floor and hit the acorns lightly with a hammer, not hard enough to obliterate them, but hard enough to crack them so that we could pry the acorn out of the shell.
Once I had done this, I noticed a thin skin on the acorn – the testa. It’s kind of like the skin on a peanut or an almond. Some people say this skin is especially high in tannins, so they feel it is imperative to remove the skins. On white oak acorns, it is (apparently) pretty easy to take them off, but on red oak acorns, which is what I had, the task is more difficult due to the large ridges on the meat which the testa sticks to very stubbornly.
As I read in the book, the best way to get the skins off is to submerge the acorns in water for five to ten minutes, stir vigorously, let them dry, and the testa should become loose and you should be able to rub the acorn against your hand forcing the skins off. Alternatively, you can wet the acorns with a spray bottle which results in less discoloration than complete submersion. That is what I did, but the testa didn’t come off so tomorrow I’m going to try the other method.
That is as far as I have gotten in my acorn processing. I now have to dry my acorns, which can take one to eighteen weeks depending on the species. Once they are dry, I shall write about my further adventures. However, if you want to read for yourself how to make acorns edible, you can read articles online or just buy Nature’s Garden. It’s about wild edible plants in general, so there’s a lot more in the book than just acorns. It seems like a very reliable source, given that it’s written by a guy who eats wild edible plants daily.
Until you’re dry, acorns!