Acorn Flour

Acorns are gathered in the fall after they are ripe. You’ll want to use your acorns within a few days of collecting them so they don’t mold or get bugs, unless you plan to store them.

If you want to store them for later use, you’ll have to dry them first. Note that drying them for storage can take a week to a month, depending on your acorns. Once fully dried they will store for years as long as you keep them dry and protected from bugs while in storage. You can use fruit drying racks or a blanket in the sun (or sunny window/sun room) to dry them, and the store them in air tight containers.

1. Gather & Sort the Acorns

I like big White Oak acorns, but any will do. The bigger the better as the more flour they will make. You’ll need a bunch of them to get enough flour, 1-5 gallons.

Next you’ll want to separate out the bad ones. For this you will need to put all your acorns into a tub of water (so there is plenty of water over them) and remove any that float. The ones that float are likely to have bugs (weevils, or weevil larvae) so remove those.

2. Cracking the Acorns

Cracking the acorns can be a laborious task. Boiling them quickly first helps with this process. In a large pot bring water to a full boil. Drop in a batch of acorns for about 30-40 seconds. YOU DON’T WANT TO COOK THEM! You’ll need some sort of container for this like a colander with a handle or a fryer basket that fits into the boiling pot.

Note that you’ll want to start cracking while they are still warm, so it’s easiest if you have a helper available.

Although you can crack with a hammer or mallet, I’ve done that before and it takes absolutely forever! It is worth the cost of a nice crank style nutcracker to  help with this step. If you must use a hammer (or mallet) then lay a towel down on a hard surface (cement, rock, etc) and then lay the acorns out, put another towel on top and then have at it! After you crack the nuts you will see a skin on them that will need to be removed. Same with any shells that didn’t fully remove from the nut. Don’t bother trying to remove them just yet, it’s almost impossible. You’ll want to dry them to release those skins and shells.

Take your semi-cracked Acorns and lay them out dry in the sun on drying racks or blankets, or alternately use a dehydrator or bake them on 200 for 20-30 min. This makes the nuts shrink and separate from the skin and shells.

Next, rub the Acorns together between your palms and the skins and shells will fall away. Separate the nuts as you work. If your palms get sore, wear gloves to do the rubbing and then go back later and separate the nuts.

Separating the skins and shells can also be done by ‘tossing’ on a windy day, like you would for wheat. Either drop the acorns from a distance into a basket or sheet, or toss them in the air and catch them in the basket or sheet.

3. Leaching to remove the Tannins

You can leach acorns while they are still in nut form, or after you’ve ground them into a mush. I find it easier to leach the nuts, however I’ll go over how to leach the mush too.

Once you’ve got all the nuts separated it is time to leach them to remove the bitter tannic acid. You can hot water leach acorns but I prefer cold water leaching as provides a more versatile end product and the flour seems to store better. The easiest way to leach acorns is to put them in a burlap sack, tie the top securely and set in a running stream for a few days or until the bitter taste of the nuts is gone. You’ll want to secure the bag into the creek really well so it doesn’t get washed away. You can also use a metal crate to put the bag in and then drop the crate into the creek. This holds it down as well as deters any little animal scavengers!

Hot water leaching is a bit more involved. It’s faster but you’ll be boiling a lot of water! Lightly boil a pot of water and add your acorns, let them lightly boil on medium for about an hour. Strain and reboil. You’ll do this 3-5 times or more, there is no way to say how many for sure, you’ll have to taste a the acorns after a few passes and see if the bitter taste is gone. When they are leached, there won’t be any bitter taste and they will taste nutty and slightly sweet.

The water from the leaching is useful in tanning hides, or for skin ailments such as poison oak and eczema (you can freeze a batch for later use). You won’t want water any plants with it as it is too strong for them.

If you decide to leach after you’ve made the flour then skip this step and move to step 4.  Grind the dried nuts into a fine flour, which is more like a meal because it sticks together. Then take that meal and put it is a muslim cloth bag and run water over it until the bitter taste in the flour is gone. Some native tribes would leach by building a mound of fine sand near a creek or river and scoop out the center of the mound. They’d place the meal in the center of the mound and cover it with a clean piece of bark to hold the meal in. Then they’d pour water over the bark/meal to remove the tannin. Then the meal was dried and re-ground into flour.

4. Grind the nuts into a mush, and then flour

Okay, finally, it is time to make the flour (or meal)!

Once your acorns are completely dry put them in a flour grinder (or food processor) and pulverize them, it creates a fairly sticky meal. You can use it like this, or for a finer ‘flour’ consistency you can dry this meal out in the sun, dehydrator or the oven. If you do this 2nd dry step, and use racks with gaps for the meal, you’ll want to put the meal on parchment paper or paper bags to prevent the it from falling through those gaps. Completely dry the meal before grinding again. The next grind will be a finer, more flour like consistency.

Store in a foolproof airtight container in a dry, dark place. Your flour should last a few months, and if you freeze it longer. But, after all that work you may as well bake bread!


Now it’s time for Acorn Bread!


  • 1 ½ cups acorn meal
  • 1 cup whole wheat flour
  • 1 tablespoon baking powder
  • ½ teaspoon salt
  • 1 egg
  • 1 tablespoons melted butter or olive oil
  • 1 ½ cups milk (buttermilk works too)
  • ½ cup honey

Thoroughly mix together dry ingredients together
Whisk together the egg, milk, oil/butter and honey.

Add the egg/milk mix slowly to the dry ingredients while you mix.

Put batter in a greased baking pan. Note that a shallow pan, like a large pie pan works better than a deep bread pan. Bake at 350° for about 30 minutes, or until lightly browned. Serve with butter and berries! Yum!