Most of us forget that humans used to eat acorns. Many ancient cultures ate acorns, and for some acorns were a staple crop for them. Many Native American cultures depended on acorns as well.
However, most modern Americans have no idea they can eat acorns. Yet acorns are nutritious, free, mostly organic, and abundant in Maryland. They take work, but they could be a fun starch to add to your diet.
Acorns have tannins, which make them bitter, but tannins can be leached out of acorns or acorn flour. Acorn flour is a mildly flavored flour that can be added to many dishes for a boost of free nutrition.
In Maryland, we are blessed with an abundance of oak trees. We have many varieties to try out, and now is the time to start looking. Though acorns aren’t falling yet, they will be soon.
Different varieties have different levels of bitter tannins. They also have different fat, protein and carbohydrate amounts. If you try one variety and don’t like it, try a different type of oak next time.
Gathering and Processing Acorns
You won’t see acorns at the farmers market. But you will see them all around Maryland in a month or two. Find a nearby oak tree that is loaded with acorns, and plan to collect some when they fall.
Acorns have weevil problems, so look for acorns that don’t have a hole in the shell. A firmly attached cap means the acorn didn’t mature on the tree. Damage to the flat disk where the cap attached or dark streaks indicate fungal problems.
You don’t have to collect them immediately. Once they start sprouting in late winter, you’ll know the sprouted ones are good and can gather them then instead.
After you collect a bunch of good looking acorns, spread them out on a sheet pan and let them dry. Dried acorns are easier to crack. As they dry, cover them to keep squirrels off.
Dried, unshelled acorns keep a long time. You can gather in the fall and plan to process your acorns later on in small batches. You can eat acorns during any season once they are dried.
To crack your dried acorns, use a hammer or mallet on the pointy end as the flat end rests on a firm surface. Some acorns have a skin on them that could be hard to remove, but you can try freezing fresh acorns before cracking them to help separate the skin.
As you crack, shell the acorns into water so they don’t darken in color if you prefer a lighter colored flour. You’ll want to leach the tannins out with water as well.
To leach the bitterness out, you can use hot or cold water. Boiling the acorn meats in water, draining, and boiling again in more water repeatedly until the water is no longer dark is one method.
If you have the time and don’t want to waste electricity, grind your acorns into flour and mix 1 cup flour with 3 cups cold water, and put in the fridge. Once a day shake your jar, let it settle 12 hours, then pour off the water and replace with fresh. After a week or two of this your flour will be finished.
Honest Food has a really great tutorial with tips and tricks for making the highest quality acorn flour possible.
Red oaks tend to have the most tannin, while white oaks are sweeter. Taste your flour as you leach it so you know when it is done.
How to Eat Acorns
Whole leached acorn meats can be roasted like nuts. Try roasting them in the oven or on the stovetop, watching for color and smell change so you know when they are done. Toasting walnuts and other nuts are done the same way, so adjust for your acorns.
Acorn flour can be ground first and cold leached or ground from whole leached acorns. Acorns don’t have gluten like wheat does, so using acorn flour straight in bread will be disappointing. Gluten is needed glue the flour together when baking. Eat acorn flour in baked goods by adding wheat flour first.
I recommend using your hard earned acorn flour at first in small amounts. Substitute a portion of wheat flour in a favorite bread, muffin, or cookie recipe. Make pasta out of it, or cornbread.
Polenta and grits are also options for your acorn flour. Depending on your kitchen equipment, you may have a coarser flour and prefer to use it in soups or as polenta.
Since different acorns have different ratios of protein, fat, and carbs, you may find different types are best for different recipes. Experimenting and keeping track of what worked best will help.
Here in Maryland, we have many native oak species to choose from. We have both white and red oaks. Since white oaks are supposed to have the least tannins, you might want to start there.
You can also start with what is nearby. Honestly, all will need some form of leaching anyway, and all are edible. While I prefer identifying what species grow near me (chestnut oaks and red oaks in my yard), you can simply go gather and eat acorns from any oak tree.
Stick to just one species when leaching so they all have similar amounts of tannins. That way they have the same processing times.
Red oak acorns have more fat than white oak acorns. Yet all have a different ratio of tannins, carbohydrates, and proteins. White oaks sprout soon after falling while red oaks sprout in spring.
Oak trees have mast years every 2-5 years, where there are a lot more acorns on that particular tree. Oaks grow acorns every year, but not all years will have the same amount.
There are many resources to help identify oak species around us. To start, white oak leaves tend to have rounded lobes, while red oaks are pointed. Red oaks also have hairs inside their acorn caps.
This year, oak trees are exhibiting flagging at their tips. This means our cicada boom caused brown tips on many oak trees. The cicadas laid their eggs at the tips of branches, killing off the leaves at the ends.
Many oak trees in Maryland are declining as well. Though oak wilt is not really a problem here, we do have oak anthracnose and bacterial leaf scorch.
Weather extremes in the last few years have accelerated white oak decline in older suburban trees. Older trees living in stressful conditions have allowed pests and diseases to further stress the trees.
University of Maryland Extension recommends deep watering of white oaks in time of drought. They say a tree that is well watered heading into dormancy is less likely to exhibit problems the next year.
Fortunately, oaks in the wild are not having the same troubles. If you have older oak trees, keep them healthy. They offer shade and cooler temperatures, not just delicious acorns.
This fall, try an old food. Save money, enjoy nature, and eat acorns!