By Laura Killingbeck

Acorns have a long history as human food.  They were eaten widely by Native Americans, and are still a food source in a number of places around the world.  Acorns are used globally in breads, sweets, pastas, and acorn tofu.

This year we had an amazing acorn season. Every time I walked across the farm, I passed so many on the ground that they started to drive me NUTS! I knew that acorns were edible, but I had never eaten them before, and I didn’t know how.  I decided to to do some research, and some trials, and figure it out.

The first person I consulted was my mom, who has her own history of eating acorns.  She is an expert forager, and each year finds something new to gather and eat from the forest.  She actually had some homemade acorn flour in the freezer from a previous year, and let me start experimenting with it, before I had finished my own batches from Round the Bend.

Acorns do require significant processing before they are truly edible.  The main issue with acorns is that they contain a high quantity of tannins.  Tannins are phenolic compounds found in most plants.  In small quantities tannins are fine to consume, but in large quantities they can cause digestive upset.  Luckily tannins are water soluble, so they can be leached out.  This is why all methods of acorn processing require some form of grinding the acorns and submerging them in water—this leaches out the tannins and is the primary factor that makes acorns edible.

Acorns are a world in and of themselves.  There are many different varieties, with different flavors and characteristics.  Within varieties, there are also individual trees that are more flavorful and productive.  For a great guide to acorn varieties, I recommend the book Acorns and Eat’um by Suellen Ocean.  This book also contains a link to what I believe is the single best YouTube video ever created—if you watch it, let me know!

Basic Guide to Making Acorn Flour

  This is the method I used to make acorn flour:

  1. Gather acorns from the ground.  You want whole acorns, with no insect damage.  If they have a small sprout, that’s okay. 
  2. Rinse them well, and soak them overnight in water.  This causes them to swell.
  3. The next day, drain the acorns and roast them in a convection oven at 400 F for 30 minutes, or until the shells split.  Your goal is to dehydrate the acorns so they shrink, while simultaneously splitting the shell so its easier to open.  Roasting also makes the shell more brittle and easier to remove.
  4. Let the acorns cool, then remove the shells with your hands.  I found that after soaking and roasting, they were easy enough to just pop open in my fingers.
  5. Put the acorn meat in a blender with some water and grind it into a paste.
  6. Pour this paste into a jar, and add at least three parts water to one part acorn paste.  The more water, the better.  Store this in the fridge.
  7. As the acorn paste sits in the fridge, it will sink to the bottom of the jar.  Once a day for two to three weeks, pour the water off the top and replace it with fresh water.  This leaching process removes the tannins from the acorns.  The acorn paste is ready when it no longer tastes bitter.
  8. When the paste is ready, spread it on a sheet in a dehydrator and dehydrate it until fully dry.
  9. Crumble the dried acorn paste into a blender or spice grinder and grind into a powder.
  10. Sift the powder with a flour sifter.(See two variations of acorn flour below) 
  11. You did it!  This is acorn flour!  Use immediately, store in the fridge for up to three months, or freeze for up to a year.

We used this acorn flour to make sourdough acorn bread, as well as acorn cornbread.  The acorn flour imparted a rich, dark color, and slightly nutty flavor.  It does take time to process, but most of it can be done as a group activity.  I had a lot of fun gathering acorns with Desa and Geoff’s two-year-old daughter, Nia.

There are also many ways to make acorn processing more efficient.  Derek Christianson of Brix Bounty Farm mentioned a tool that you roll across the ground that gathers nuts inside it—perhaps this could work for acorns.  Lu Yoder, our neighbor who creates bicycle-powered farm tools, discussed the attributes of his homemade shelling and winnowing machines.  If you want to incorporate acorns into your daily diet, there are certainly tools that make this process easier.

I enjoy the flavor and color acorns provide in bread recipes, and I love the fact that acorns literally “fall from trees”.  I don’t have to prep any soil, prune, or do anything at all—the acorns just come to me, falling from the sky!  In the end, no matter what tools you use, or what recipes you make, part of the joy of eating acorns is in the magic of finding something wild and edible right under your feet.

Honey Gold A-Corn Bread

This recipe is a Round the Bend Farm original!

Makes one 9 inch pie pan.

Ingredients:

2 cups masa (fresh ground nixtamalized corn)

1 cup acorn flour

2 eggs

2 tsp baking powder

1 tsp sea salt

¼ cup honey

½ to 1 cup milk (quantity is variable based on moisture content of masa—start with ½ cup and increase from there)

¼ cup butter or lard, melted

¼ teaspoon ground nutmeg

Instructions:

  1. Preheat oven to 425 F
  2. Mix ingredients together until fully combined.  Batter should be only just pourable.
  3. Grease a 9 inch pie pan and pour in the batter.
  4. Bake until firm in the center.  Moisture content affects baking time—check after 20 minutes, but you may need to bake for longer.
  5. Cool before cutting.

Acorn Loaf Bread

You can also replace five to ten percent of wheat flour with acorn flour in most bread recipes.  We have been doing this with our artisan sourdough loaves.  The acorn gives the bread a rich, dark color and hint of nuttiness.