“When an oak-tree is felled the whole forest echoes with it; but a hundred acorns are planted silently by some unnoticed breeze.”
-Thomas Carlisle, 1795-1881
Our Thoughts:
The smell of boiling acorns is entirely unexpected. From the bubbling pot, tendrils of steam curl up, bearing the familiar oakey scents of brown sugar and vanilla that are found in some wines, compliments of the cask they were aged in. Together, absurdly, the boiling mixture smells like creme brulee.
The resulting flour also tastes sweeter than we anticipated, with a subtle nutty flavor. It is very rich in protein, so a little goes a long way. We began mixing some in with our oatcakes, and have been very happy with the result.
We had expected this post to be a grueling sort of undertaking, and were pleasantly surprised to find how straightforward it is. It is a nice project to have going on the side while you prepare the real meal of the day. We boiled and strained ours three times just to be sure we got rid of the bitter tannins, but two times probably would have been sufficient.
So, with relatively little work, acorn flour is a definite win in our book!
How to make Acorn Flour
This looks complicated, but is actually relatively easy.
What you’ll need:
- Acorns!
- Something to bust them open with
- a pot or other means of boiling the acorn meat
- cheesecloth, old t shirt, or dishtowel for straining
As with other nuts, you’ll need to remove the shell of the acorns to get at the meat. There are different ways to do this: Nutcracker, pounding it with a hammer and removing the nut meat, or cutting them open. We are lucky enough to have a giant mortar and pestle for making guacamole, and that worked brilliantly. Just a couple of hard whacks per acorn splits the shell sufficiently. Fish out the meat and discard the shells.
Once all the meat is collected, pick over it to make sure that none of the pieces are black, molded, or otherwise dodgy looking. The next step is to grind down the acorn meat. This was traditionally done with two stones that worked like the mortar and pestle described above. However, since we live in a modern age, and love our modern conveniences, we opted to use them in favor of being able to do anything else all day. We threw our shelled acorns into the blender and worked the buttons until the consistency was as fine as it seemed it would get. If you try using a blender, you might pour a little water in with the grounds to help keep them moving.
Because of the tannic acid in acorns, they have to be boiled to remove the very bitter taste. While some acorn fans report that acorns from white oaks don’t need boiling, we recommend at least one round of boiling just to be on the safe side. To do this, bring a pot of water to a boil and pour the acorn meal in it. Keep at a boil, stirring the pot once in a while to keep the mixture from sticking to the bottom.
Once the mixture has boiled for about 5 minutes, the water should be a murky sort of color. You will want to prep your draining system in the sink. We draped an old t shirt over our collander, and poured the liquid into that, making sure that we didn’t pour too much in all at once. Rinse with some cold water to help cool the ground acorns down before picking up the cloth and squeezing the water out.
After each boiling, you’ll want to tasted a piece to see how it’s coming along. Grab a larger chunk rather than a smaller one- don’t be shy! If there is no trace of bitterness, you can move on. If it still tastes bitter, back into the pot! Keep boiling and straining until all the bitterness is gone.
When you are done, you will be left with a mushy ball of acorn paste. You can use it right away or dry it out for storing. We nibbled a bit of ours, then spread the mixture out on a cookie sheet and put in outside in the sun. You can also slowly roast it in the oven at a very low temperature, but we liked adding the sunshine into the mix.
Voila! You have acorn flour! You can choose to grind it down further in a food processor, or leave it as is. Consider adding some as a flour replacement to bread, pancakes, or other baked goods. Or, make a paste of it and serve with squirrel and pickles…
This is great. There’s a billion different kinds of acorns that fall all over my backyard and I’ve been researching different things to do with the ones I can get to before the squirrel army seizes them. Did you use any guides/references for foraging your acorns or did you get them from a store?
If you don’t want to go to that much trouble, Korean markets carry already-processed acorn flour.
I’m intrigued, mainly due to the mountain of acorns in our back garden. Will have to give this a try, especially as the 7yo is now collecting them all together. :)
Rflong,
After the kid harvests your acorns, put them in a sink (or bucket) of water. Any that float are infested with bugs or worms: throw those out and shell the good ones.
It’s *still* easier to patronize a Korean market! :) I’ve used acorn flour in baking before, just to see what it was like.
My dear daughter and I are working on it right now. We are at the first boil stage of bur oaks. We found out that the acorn will not mold as fast in the shell as we pre-shelled some 1 week ago in anticipation of the “acorn making event..”
Yea! Dear Daughter and I finished making acorn flour with Burr Oak acorns. Shelled easily , tossed in blender with water to cover and blended till looked like corn meal. Toss in to pot , boiled for 10 minutes, strained tasted great with no bitterness but DD wanted to boil again. She was eating it by the spoonful. Boiled, strained and blended again until it had a smoothy look. Then squeezed it and used it as 1/4 of the “Flour” in pumpkin muffins. They are great. Will use more next time. She felt so empowered by the whole process of living off the land.
I understand if you blend it with some olive oil you can make Acorn Butter.
Fun fact, tannic acid was used to treat animal hides and make leather. That’s why it was called “tanning” a hide.