After last year’s misadventures in leaching acorns, I hadn’t planned to try again this year. (If you’re curious, you can read about it here and here.) Or, you know, maybe ever. It seemed like too much bother. Even after I attended a foraging class where the instructor said that by foraging acorns, you can harvest a month’s worth of calories in a single day. I mean, that is great for a month, and then at the end of the month you are sick of acorns and out of food again! Plus a day of gathering the acorns doesn’t include the time and effort to sort them, shell them, leach them, etc etc. I wasn’t buying it. Besides, I don’t have any oak trees close enough to make good (easy) foraging.

But.

I found myself in a local park with red oak trees just DUMPING acorns on the ground. There were literally treacherous spots to walk, the acorns were so thick underfoot. 

I couldn’t help it. 

I gathered up a few pounds, and the saga of the acorns began yet again. 

Only this time, I actually read the relevant section of Sam Thayer’s book, Nature’s Garden. And honestly I was aghast that I had even tried processing acorns last year without doing a little more (or basically any) research before starting! If you are going to try acorns, I highly recommend his book.

The first thing I learned was that acorn weevils are just a thing, and a float test (because the partially eaten acorns tend to float) doesn’t always work.

There are “tells” on the acorn shells that purport to reveal when an acorn is infected, but I haven’t gotten the hang of those yet. I may return to the park in late November – after the acorn weevil parents are done for the year – and collect another batch.

I lost a third of my acorns to the float test. After the float test, I toasted the acorns at 350 for five minutes to help encourage the nut meats to separate from the shell. Apparently it is even better if you can let the acorns dry for several weeks first – they can actually be safely stored this way for years, according to Thayer – but I’m impatient. (Also, being able to store dried acorns for an extended period of time gives me more faith that acorns really could be used as a source of dietary calories in the fashion implied by my foraging instructor.)

Following the baking, I laid the acorns out on a towel like Thayer described… well, sort of like he described. I should have folded the towel lengthwise for a longer, narrower arrangement of acorns. 

I used the tamping end of a post hole digger to crush the acorns, two by two. This was followed by another round of sorting, since once you could see the acorn flesh it was obvious some were infested, and others just spoiled.

Then the fun part: separating the nutmeat from the shells. I’m kidding, it wasn’t fun. It was almost as tedious as rolling amaranth seedheads between your palms to get the seeds to fall out. Luckily I had company, but the hours still dragged by as I carefully plucked the nutmeats out. Maybe I should have toasted them longer to help detach the nutmeat from the shell because there was still a lot of work using picks to gouge them all out.

I think in pre-industrial societies, more people had to do this kind of work and people tended to do it together so it was a social opportunity and less tiresome for all involved. Nowadays no one seems to even know their neighbors, and I can only imagine the reactions if I walked over and asked if they wanted to help shell acorns!

My biggest mistake last year was trying to leach chunks of acorn, rather than acorn flour. The acorn’s tannins are water soluble, and the more surface area available the more effectively the water can do its job. I used my food processor to grind the acorns into a meal. Probably not as fine as would be ideal, but the best I could manage with the equipment I had.

After reading the pros and cons of each method, I opted for the cold leaching approach. Which by the way, ended up being exactly the same as the “lazy leaching” I tried last year with a few improvements. Namely, more patience and ground acorns.

Only…this necessitated a bag.

Which came with its own problems.

Yes, really.

I had thought about buying jelly bags in the past, but never had a real reason for them. So I went online (as one does) and was immediately confounded by a moral dilemma: natural cotton, or nylon? Natural cotton seemed more appealing at first, but the more I have learned about the cotton industry (pesticide overuse, anyone?) the less keen I am. Plus, cotton apparently can absorb odors and flavors from foods over time. Nylon, on the other hand, does not absorb odors or flavors, and is one of plastics least likely to leach chemicals into your food. But it is still a petroleum-based output of industrial manufacturing. And actually, I shouldn’t be buying anything because this is just another knee jerk American consumer reaction. I have a problem, therefore I must buy a product to solve it. (Otherwise stated, “I shop therefore I am”.) 

Since I didn’t have any good basis for making a decision, I chose a bag that made me laugh. Makes me laugh every time I look at it, honestly. And that is worth something!

Of the two bags that came in the set, I used the less-fine mesh since the acorn meal was relatively coarse. For three days, I soaked the acorns in water with “when I remembered to” water changes. I did not keep track of how many times I actually changed the water. But I kept an eye on the water itself, and over the three days it became less cloudy and colored each time I changed it.

I also nibbled the acorn meal periodically. After a full day it had already lost the mouth-puckering effect that tannins usually cause. By day three, the flavor was, well, unremarkable. Which is what I was hoping for! What I was NOT expecting: the acorn meal turned darker as the days went by, ending up the color of coconut sugar or cane sugar. 

To dry the sopping wet acorn meal, I spread it on a cookie sheet and put it in the oven on “warm”. After an hour (with periodic stirring), it still seemed wet, and smelled like it was actually starting to cook despite the low temperature of the oven. I resorted to my backup plan – using my regular food dehydrator. I have become more leery of using it since learning more about how plastic (especially heated plastic) can leach chemicals into foods.

I ran it for the least possible amount of time to get the acorn meal dried out, just a few hours. I then ran it through the food processor again to break up clumps and attempt (and fail) to get a finer texture.

The real test of course is actually using the acorn meal. Since I choose not to eat grains, I already eat “weird” food. My hope with the acorns was a local and sustainable replacement for almond flour. Because the acorn meal was new and untried, I opted to replace half the almond flour in a chocolate chip cookie recipes as the first experiment. (OK, let’s ignore for the moment all the ecological implications of chocolate chips!) The acorn meal definitely changed the color of the cookies, which caused a bit of disconnect when eating them because they “looked” like they should have cocoa powder or cinnamon or something else in them causing the darker color. But the flavor and texture was exactly what I expected. Obviously not your standard Tollhouse or Nestle cookie, but pretty good for a grain-free treat. (Here is the recipe I used if you are curious.)

Overall, I am pleased to call this a foraging success! The real question, of course, is whether I will do it again. Was it worth all the work and time that went into it?  I’m going with a qualified “yes”. The only part which was truly “work” was separating the nut meats from the shell, and I think (hope) that will be easier with acorns that have dried for a few weeks or a month before processing. And finding a sustainable substitute for almond flour is very important to me. I planted hazelnut trees for this reason; unfortunately they are still a few years away from providing any nuts. Acorns may help me fill that gap in the meantime.

Yes, I understand that one person avoiding almond flour is not going to solve ecological degradation in California, or slow global warming because less almond flour is being trucked to Maryland. But maybe one other person will try acorns after reading this blog. Or a few. And maybe they will inspire their friends and associates to give acorns a shot. And maybe enough of us together will make a difference.

More on Acorns

If you are curious about the nutritional value of acorns, you can find information online, such as this site. 

Also a few years ago Scientific American published an interesting article about reintroducing acorns into the human diet, which can be found here.