I would wager that at some point in your life, probably when you were a little kid, you stood under an oak tree holding an acorn and looked up thinking, "that big tree came from this little thing?" If you're like me, that experience was one of the first where you realized life - as in life on earth - is pretty darn amazing.
You may be surprised to learn that for many cultures' ancestors, the acorn was more than just a symbol of the wonders of life - it was a major food staple. Among others, there are records of the ancient Greeks, Iberians, Japanese and English eating acorns, especially during times of famine when grains were unavailable. Contemporary Native American and Korean cooking incorporates acorns in beautiful dishes that you can still find today.
It takes effort to make acorns palatable for humans. They contain bitter tannins that can be toxic and cause irritation, so we have to leach these tannins out in order to cook with acorns. The processes devised by ancient peoples to do this are pretty incredible and required hours of work, but in today's modern kitchen we can do the same work in only a fraction of the time. So this season, take advantage of the tons and tons of acorns littering the ground around you and make something amazing!
A Brief History
People have subsisted on acorns for millennia. Basically, wherever you can find ancient people living under oak trees, you can find recipes using acorns. They are nearly a perfect food for the pre-modern human: they are easy to gather, they store well and they contain a good amount of protein, fat and carbohydrates. Because the amount of acorns that oaks produce varies year by year, people would gather acorns in years of plenty and store enough to last for a couple years.
The preparations for using acorns are as varied as the cultures that prepared them. Most ancient peoples ground acorns to make meal, which they used in many of the same ways powdered starches are used today. In some ancient cultures, the lower classes would substitute acorn meal for grain flour, especially during years with poor crops.
In most areas of the world where acorns were eaten, as the availability of grains expanded, the use of acorns dropped off.
- Before food processors, metal sieves and bowls were ubiquitous, cooking anything more complex than grilling took some effort. When it comes to something as complex as running water repeatedly through acorn meal and then baking with it, the processes developed by some cultures are fascinating. To get an idea, check out this 1960s video of a Native American woman demonstrating how the Southwestern Pomo people prepared acorn meal. Because of her work, it's is probably one of the coolest videos I've ever seen.
- Oaks greatly benefit from the help of animals to spread their acorns. The best buddy oaks have in this regard is the squirrel. Sure, once they squirrel away their stashes, they have an amazing sense of where the acorns are and will return for their winter snacks. But invariably they'll miss a few or can't make it back to their buried treasure. Boom: a new oak lovingly planted.
- In times of war, some soldiers used ground acorns as a coffee substitute. Acorn coffee was made during the American Civil War and the Germans made their own version during the World Wars calling it ersatz coffee. Here's a video of how to make your own acorn coffee.
- Acorns are all over heraldry. They mean a number of different things because the symbolism of heraldry isn't easily defined. For instance, check out the reason acorns can be found in Kate Middleton's coat of arms.
- You haven't lived until you've seen an acorn weevil and what it does to an acorn. And what its kids do.
The oak tree is one of America's most common species of tree. You can find them everywhere. As far as acorns are concerned, you can make acorn meal out of any acorn, but a few specific varieties of oak are better, for reasons explained below.
In general, what you're looking for are big, healthy trees. You'll also want to look for multiple stands of oaks in different areas. Because the amount of acorns put out by oaks vary year by year, having multiple stands to check helps average out the chances that you'll strike acorn gold. Be warned though, particularly rough years of drought or extreme weather might affect acorn production for your entire area.
When looking for your oaks, it's also helpful to check out what's going on under the tree. Stick to trees that don't have a lot of underbrush so that finding the acorns isn't a chore. Finally, when going out to gather acorns, find ones that don't look like they've been sitting on the ground for a while, because they might have started germinating. Squeeze the acorn - if its shell is pretty hard, you're likely good to go.
On the list of other things to consider when foraging for acorns: bugs. As in bugs within the acorn. If you were a curious (nerdy) kid like me, you've split open a fair share of acorns and maybe were surprised to find a bug inside. In most cases, these are the larvae of acorn weevils or other insects. I can't blame them - a nutrient-packed, well-protected acorn sounds like the perfect spot for me if I was a baby bug. But I can also understand not wanting to chop up acorns only to find you've sliced up a bunch of insects, too.
You can check if your acorns are buggy while still at the tree. In some cases you'll be able to tell if your acorns are infested because there will be a little hole in the hull of the acorn, which means the bug has eaten its fill and left home. You can also smash open a couple of acorns to see if you have any insect stowaways. If you find a bunch of infested acorns, move on to the next oak.
The more surefire way to ensure your acorn hunt is easy is to follow fire. In case you didn't know, many Native American tribes habitually used fire to reshape the landscape of pre-colonial America to their benefit. Considering the wildfires of today, many folks are surprised to learn that much of America periodically burned because of natural causes like lightning strikes. For many reasons, fire can be an important part of a healthy forest and actually prevents the intensely destructive fires of today.
As for acorns and oaks, fire kills the insects that infest them and clears the underbrush out from under big oaks without killing the trees. This makes gathering bug-free acorns a synch. Today, many public forests managers and farmers practice controlled burns to manage their forests. Contact your state's department of natural resources or conservation to find out where they've performed controlled burns in your area and go after those acorns with abandon.
Typically oaks begin producing acorns in the late summer and they drop throughout the fall.
As a significant proportion of the world's deciduous forests, oak trees are some of the most important life forms around when it comes to combating climate change. Because they do such great jobs of trapping carbon and cooling the planet, collectively oaks do far more in the fight against climate change than do many of us humans. With their wide root systems, they're also great at erosion control.
Oaks are a major source of shelter and food to tons of woodland animals. Of course there's the squirrel that buries acorns everywhere to save them for later months (this practice also works to leach out tannins, by the way). Then there are mice, bear, rabbits, deer birds and other animals that also eat acorns in varying amounts. While some animals have evolved to handle tannins better than others, horse and cattle should steer clear from eating a lot of them. Hogs are huge fans of acorns and some argue that acorn-finished hogs make for the highest quality pork.
Characteristics and What to Look for
Not all acorns are made the same. As you've probably seen, acorns come in all shapes and sizes, from tiny little dudes to long ones to furry-hatted burr oaks. There are also significant differences in their tannin content. Some oaks, like the common red oak, are high in tannins and require a lot more leaching than other varieties. Luckily for many of us, the white oak is fairly common and produces acorns low in tannins. They have a rich, nutty flavor that deepens when roasted. Some varieties, like the California black oak, are particularly useful for producing acorn meal and were preferred by the California Native Americans who ate a lot of acorns. Here's a great field guide to telling different kinds of oak apart.
Nutrition and Affects on the Body
As mentioned above, acorns are little bombs of nutrient-packed goodness. Like other nuts, they have a high concentration of proteins and fats. Acorns are high enough in these that they can spoil if not properly stored. Since the nutrient qualities of acorn vary by oak variety, there are different and amazing uses for many kinds of oaks. All of them are gluten-free, however.
What to Do with It and Cooking
The leaching process is pretty easy and straightforward as you can see in the basic recipe for acorn meal below. Once you've made your meal, it can serve as a highly nutritious substitute in any recipe where you would use cornmeal. Acorn gives bread a nutty, rich flavor that's reminiscent of chestnuts and fall.
Acorns are also great in flatbreads, tortillas, cornbread-type confections and honey cakes. You can press them into acorn oil and it's apparently some pretty cool stuff. Because of their nutty flavor, food made from acorns pair well with savory dishes. For a truly woodsy breakfast, use acorn meal to make pancakes and hit them with real maple syrup. Over at the blog "Hunter Angler Gardener Cook," Hank Shaw's use of acorns is to be admired. Spend some time checking out his recipes and insights.
Other delicious ways to use acorns are Korean preparations. There are two famous acorn-based dishes in Korea that use acorn starch. One is dotori guksu that features acorn noodles. The other is dotorimuk, which is basically an awesome acorn jelly.
Acorn Meal How-To
Step 1 : Shelling and Chopping
Once you've gathered your acorns, you'll have to get the shells off. There are a couple of ways to do this. You can hit them with a hammer or you can cut them in half and shell each side. Some varieties of oaks, like reds, have a skin on the meat of the acorn called a test. If you freeze your acorns fresh, then thaw, the test comes off more easily. Drop the hulled meat into water as you work to maintain their beautiful color.
After shelling, pulse them in a coffee grinder or food processor or chop them into tiny pieces. The smaller the chunks, the faster you'll get the tannins out when leaching, but be sure to not grind them too much so that they might pour out with the water.
Step 2 : Leaching
The best way to leach your acorns is to submerge them in a flowing stream for a couple of weeks. But you probably don't have the time or the stream for that. So, there are two ways to leach your acorns: the hot way and the cold way. (The hot method is much faster but the process of boiling harms a starch in acorn meal that helps it glom together like wheat flour does. So if you're planning to bake with acorn meal and not use other flours, it's best to stick with the cold method.)
For the hot method: bring your acorns to a boil in a good amount of water, pour it off and then repeat. This takes a couple of hours and multiple batches of water (the number of batches depends on your acorn's tannin levels) and ultimately not a lot of effort. For the cold method: put your acorns in a big jar and let them sit in the fridge. Every day, shake the jar, pour off the water, refill and let sit again. Do this for a couple weeks. For both the hot and cold methods, you'll know the acorns are ready when you chew one and it doesn't taste bitter or make your mouth feel pucker-y. Just make sure to not pour the water down the drain - you can use it as you would any grey water.
Step 3 : Drying and Grinding
Once you've leached your acorns, it's time to dry them. If it's warm out, spread the acorns evenly on a tray and let them dry in the sun. You can also dry them in your oven on its lowest setting or in a dehydrator. Once dried, you're ready to go! Grind them in a food processor, sieve out the big chunks and grind them again until the acorns have become a very fine powder. Now get cooking!
This post was originally published in October 2015.