Thursday, November 20, 2014

Making Acorn Flour!

If you have ever processed black walnuts you may be hesitant to ever attempt to use other foraged nuts. I am happy to report that acorns are much easier to use! This was a good year for acorns as not every year produces an abundance. It has been said that trees produce a lot in advance of a bad winter.  That remains to be seen!  I have noticed that it runs in a three year cycle, two being few nuts while the third being prolific.

You really want large nuts with small caps. The smaller the cap the less bitter due to tannin. Look for a white oak tree. It has the traditional oak leaf but with rounded edges. Unfortunately, all we have locally, that I can find, is red oak. Red oak works but will require a longer soak to remove the bitterness.

Collect your acorns.  Try to collect as soon as they fall and not after they have sat on the ground for a long time. Examine the nut to be sure the shell is intact and has no holes. Some people will put the nuts in water and toss those that float as those may have worms.  Spread out and allow to dry for several weeks or you can speed this up with a dehydrator or low oven. This shrinks the nut and makes it easier to shell.

Use a nut cracker and remove the shells. Shells are thin and crack easily.

Acorns generally come out whole without much effort. Acorns should have a brown exterior with a white interior. Throw out any that are black.  Have a knife handy to cut suspect acorns in half to be sure they are good.

Soak whole nuts overnight to soften. Drain. Liquid will have tannins in it.

Blend nuts with some water into smaller pieces but not into powder size. You want to increase the nut surface to leach the bitterness out but not so small that straining becomes difficult.

Place nuts in a strainer that fits into another larger pot. I used a steamer pot that has holes on the bottom which I placed into a large pot.  This way you can just lift the pot out to strain and add more water for the next soak.

Soak in hot water but not boiling.  I used hot tap water.  If you boil it, it will change the texture.  It will cook the starch and will no longer clump together in baking.  Change the water frequently. I planned it for a day when I was already going to be in the kitchen canning so about every hour for a day the water was changed. Taste for bitterness. By the end of the day, it was nearly bland enough. I set it to soak overnight and by the next day it was ready. Strain

Spread out nuts to dry. You can use a dehydrator or warm oven. I used my oven set at 115 degrees. It took a day to completely dry.

Once dry, grind into powder. A small coffee grinder works great!

Store in your refrigerator or freezer for best results.

This was far less labor intensive than processing black walnuts which is a dirty and time consuming process with little to show in my opinion. Acorns take time but are easy to process and produce a beautiful flour.

If you are local to Nashville, Tennessee, check out Vanderbilt's campus for an abundance of acorns.  The acorn is the school emblem for a reason.


  1. Thoughtful of you to illustrate your steps with photos, Dr. Mom. My technique is very similar to yours except when it comes to leaching and drying, and then it is a lot faster. I put a cup of shelled acorns in the blender, fill it with water, and process it for two minutes. I pour the slurry into a dishtowel-lined colander set in my kitchen sink, and turn the water on to the point where I can stir the slurry around with a wooden spoon without losing any of it over the top of the colander. With the water running, I stir for 8 minutes, then turn the water off. What remains looks very much like damp sand. I taste a pinch to check for bitterness. If it is still bitter from tannins, I turn the water back on and stir for a few more minutes. The fastest I've ever produced satisfactory red oak acorn meal is 8 minutes. Sometimes it has taken 11 minutes. Bur oak acorns have required 15 minutes. White oak acorns took 10 minutes. I bring up the ends of the dishtowel and squeeze out as much water as possible, then freeze the meal while it is still damp. Drying it is not necessary, as long as you add the damp meal into your recipes after adding water. The flavor and texture of the baked goods is superior to using dried acorn meal or acorn flour. My preference is to vacuum seal two cups of meal at a time in a labeled quart bag, pressing it flat. The flattened bags quickly freeze, and can be thawed out in minutes in a bowl of warm water. Vacuum sealing them this way keeps them good for years, so I always have enough between good mast years.

    1. Mike, I tried your method today and it is brilliant. So much faster and it really works great! Wow, thanks!

  2. Thanks, Mike! I look forward to trying your technique next year!