How to Harvest, Process, and Eat Acorns

I’m not a Luddite, I fantasize about a faster internet connection probably more than most people and I think there are ways for our technologies to partner well with the living world. What worries me is when we try to replace parts of the living world, as if they are replaceable. Replacing “acorn” with “bandwidth” might seem trivial, but words matter. If you take away words, it makes the thing that word represents much easier to forget.

“Acorn” might seem like a small loss, but there is nothing small about an oak tree or its importance in the world. Oaks support more insects and animals than any other tree on the planet, with the current research tallying more than 4000 species that rely on them. I don’t know if they counted humans on that list, but they should.

I relate to the world mostly through the lens of food, so my rally cry for the acorn comes from the kitchen. People tend to agree that food is a fast track to most human hearts, and I’m certain that once you eat an acorn, you’ll never forget its name. Luckily, there are over 90 species of oaks in North America alone, so almost all of us can easily find the joy in a stack of acorn pancakes.

“Balanophagy” is the word for the practice of eating acorns, and while that word and that practice have largely been forgotten, the acorns don’t forget to fall. There are many acorn-eating methods that people have employed throughout our long history together. There are countless resources available in books and online by people who have found all kinds of interesting ways to use acorns in their modern lives. My personal favorite is Sam Thayer’s extensive chapter on acorns in his book “Nature’s Garden.” I’ll cover the basics here and hope you develop your own innovations—heck, maybe even technological ones.

Collecting Our North American oaks can, with a few exceptions, all be lumped into the “red oak group” or the “white oak group.” The white oak acorns germinate quickly after dropping and need to be processed quickly, while the red oak acorns don’t germinate until the following spring, which gives us extra time. You can collect by hand, with a rake and shovel, or using specialized tools like the Garden Weasel Nut Gatherer that I’ve really been enjoying.

When collecting by hand, you’ll want to sort out bad acorns as you go, while if you’re collecting with a tool, you’ll need to sort afterward. Give a visual inspection for attached caps, holes, discoloration, mold, and bulging or rippled shells. You can finish with a float test (this only applies to very fresh acorns) by putting your good-looking acorns into water and discarding the ones that float.

Drying Acorns, especially those in the red oak group, will store in their shells for years if properly dried. If you have a dehydrator, they take about 24 hours at the lowest setting. If you don’t have one, the acorn harvest often coincides with the first fires in the woodstove, which will speed up drying quite a bit. Essentially, you want to spread your acorns in a single layer in baking trays, cardboard boxes, screens, drying racks, cloth bags, empty drawers (use your imagination here), and keep them somewhere warm, dry, and rodent-free for a few weeks. Crack a couple every few days to check progress. Once they’re hard as a rock they can be stored and processed.

Shelling There’s really no wrong way to crack a nut. You can use a mortar and pestle, a rock, brick, hammer, or nutcracker. All will get the job done. Cracking acorns is one of those “it takes a village” kind of tasks, so, if you have people around—employ them. It’s slow but satisfying work, and a usable amount can be done by one person in an evening while watching a movie.

I highly recommend treating yourself to a Davebilt Nutcracker for processing larger amounts, it can breeze through up to 20 gallons per hour. Once cracked, separate the nutmeat from the shells. I do this by hand, but there are also winnowing and water separation options depending on the species. Next, the nuts will have papery skins called “testas” clinging to them, and these should be removed. They usually fall away freely from roughing them up in your hands, but if they cling, rubbing them over hardware cloth should do the trick.

Grinding If you’re hot leaching, you can keep your nuts in halves or large pieces for the leaching process and then dry and grind as needed in a mortar and pestle, grain mill, or food processor. If you’re cold leaching, you need to grind beforehand, which I find most easily done in a food processor with a ratio of 1 to 3 acorns to water.

Leaching Don’t skimp on leaching. That’s my number one piece of acorn advice. All other parts of this process can be innovated to your heart’s content but leaching just takes as much time as it takes. I’ve made the mistake of under-leaching a big batch of acorns, and everything I made with them was awful. Don’t let your efforts go to waste by getting impatient at this stage—you’re almost done.

Hot leach by covering your nut pieces in hot water and boiling for 30 minutes to a couple of hours. Drain the water and repeat this process, sampling the nutmeat along the way. This can take any number of water changes; the only measurable “doneness” is when you taste absolutely zero bitterness. Dry these as large pieces or grind and store as flour.

Cold leach by covering your ground acorn meal with cool water, stirring or shaking, and letting it sit for a few hours or overnight. Pour off the water, slowly, and repeat for a couple of days to a couple of weeks. I like a half-gallon or gallon jar for this process. I’ve had better luck cold-leaching red oaks at room temperature, but white oaks spoil more easily and should be kept in the fridge. When it tastes done, your absolutely-not-bitter-acorn-meal can then be drained through cloth or a strainer and dehydrated or spread thinly on baking sheets in the sun or a low oven to fully dry before storing. Be sure to drain the last change of water into a pot and drink this “acorn milk” warm with maple syrup.

Eating I like my hot-leached acorns in larger pieces so I can rough chop them in small batches for texture in baked goods, hot cereals, and chilis. I use them mixed with, or in place of, ground meat or beans. I pickle them in tangy brine to eat with charcuterie. I candy them in maple syrup, liquor, and butter and pour over ice cream, sub them in for pecans in a batch of sandies and for walnuts in baklava, or grind them into flour and mix a 1 to 1.25 ratio with wheat flour for pancakes, tortillas, pie crusts, and pasta dough.

If I cold-leach a coarse-ground meal, I love to use that as grits or folded into cornbread batter. If your cold-leached acorns are finely ground, then that flour can be used for baking without adding wheat flour. It won’t rise very high, but it’s perfect for dense, crispy, or chewy things like pie crust, pasta, flatbreads, and crackers. I find new reasons to love acorns every year. Just the other night I made pozole with acorns instead of hominy and it was so good I doubt I’ll ever use corn in that dish again. Stick to these tips and you might find acorns replacing some of your cooking mainstays, too.