The power of the mighty oak acorn

Back when metro cards were more common here in the city, I wondered how many of the stray cards I saw lying around I would need to swipe to find one with a ride left on it. I learned recently, if you are interested in foraging for your transportation, you just need to collect some of those discarded vape pens you find in the flotsam in our streets.

I was impersonating such flotsam a few weeks ago, stretched out on the couch, and letting YouTube present me with videos, when I clicked on one created by a young British man who assembled an e-bike battery using disposable vape pen batteries. In the video, he showed how you can disassemble these bits of urban confetti to reveal the small but reusable battery inside. He gathered one hundred and thirty discarded vape batteries, unwrapped them, rewired them, and carefully packaged them into a new battery — with the addition of $80 in materials — with enough power from a single charge to travel twenty-two miles on dirt trails without pedaling, hitting a top speed of thirty-two miles per hour.

Sometimes, foraging for food is also about gathering up little bits of energy that would otherwise be crushed under a car tire. Little packets of energy that we typically don’t have the time to figure out how to use. We are still experimenting with processing and using them in food, but our family has been picking up acorns when we pass by a productive oak at a convenient time.

Processing and using acorns well is a somewhat involved topic, so I will try to give the nutshell version here. I hope to follow up on this article with a detailed look at some of the food we create with our acorn flour.

It is helpful but not absolutely necessary to take note of the type of oak tree that you are gathering the acorns from, as red oak and white oak species produce acorns with slightly different characteristics. White oak acorns, for example, can take months to dehydrate in a warm, dry place, while red oak acorns will dry in several days. This is likely due to the higher water content of white oak acorns. Acorns have the potential to become moldy or rotten within a few weeks of being collected, so you can either process them within a few days, store them in a refrigerator for extended periods, or dry them for long-term storage — potentially for years if done properly.

Shelling acorns, fresh or dried, can be as simple as cracking them with the shoe on your foot, tapping them with a rock or hammer, or investing in the $273 Dave-Bilt #43 nutcracker, which can shell fifteen to twenty gallons of acorns an hour. We opted for the simple method, each of us wielding a hard implement of some kind to crack shells and separate out the nutmeats. Be on the lookout for acorn weevil grubs as you open your acorns — they can be a pleasant surprise or an unwelcome one, depending on your feelings about wiggly larval things. If you are feeling adventurous, collect them in a small cup as you work and fry them in butter, salt, and your favorite spices (or sugar) when you are done.

After shelling, you can choose between cold leaching or hot leaching, processes where you use water to remove the water-soluble tannins from acorns that give them their bitter taste. Hot leaching involves boiling pieces of acorns (boiling ground acorns will turn them into a sticky mess) in water for thirty minutes, an hour, or two, replacing the water and boiling it again — until the acorns are no longer bitter. The advantage to hot leaching is speed; the disadvantage is that, unless you are boiling on a woodstove that also happens to be heating your space, it is using a lot of energy. The resulting flour is also stripped of more of its nutrients, compared to cold leaching, and does not stick together when cooked.

In order to cold leach our acorns, we placed the shelled nuts into a blender with a little bit of water and made a puree. Then we poured the puree into a coffee filter, supported inside a strainer, over a bowl. The water drained through over the course of thirty minutes or so, and we poured more cold water over the ground acorn flour. We did this several times until the acorn flour was no longer bitter and the water draining through was relatively clear.

Grab some acorns nearby and stay tuned for our adventures in acorn flour cooking!