How Not to Cook Acorns

Image: upper bowl, acorn meal; lower plate, partially eaten acorn muffin with apricot raspberry jam.

I’m working on an article about urban foraging in Washington, DC, that is, finding and preparing edible wild plants downtown. Other cities, like Portland, Oregon have extensive urban foraging communities. I have been in contact with a handful of Washington’s urban foragers, but have not yet found a cohesive community. I plan on looking harder.

I have, however, met some interesting people with extensive knowledge of local edible wild plants. Based on my initial research, I’m finding that many of the areas wild plant gatherers look for food in DC’s expansive green areas, like the city’s northeastern and northwestern neighborhoods.

My neighborhood is kind of brown by comparison. Although many wild edible plants grow within a block of my house (including dandelion, chicory, horse mint, wild mint, wood sorrel, and nasturtium), green spaces in my neighborhood are either private landscapes or the grown-over remains of demolished old buildings where many dogs pee often.

I’m also researching whether or not the city sprays its vacant lots with pesticide before I make a ghetto grass salad.

Acorns seemed safe by comparison. They now litter the sidewalk and, it turns out, are not just for squirrels (or pigeons, pigs, deer, mice, rats, and lots of other animals). Humans have been eating acorns for millennia, though today they are not especially popular except in North American Indian and Korean cultures. Acorns are nuts and contain high levels of protein, carbohydrates and fats, and essential minerals. But they are often too bitter to eat without processing. My dog hoovers most everything he finds on the sidewalk including napkins, cigarette butts, diapers, and mysterious lumps but consistently spits out acorns.

Tannins cause the bitterness (the word comes from the Old German “tanna,” which meant oak). Tannin levels vary depending on the species. Most DC oaks are high-tannin red oaks. White oaks’ acorns are reportedly low enough in tannins to eat without leaching away the bitterness. Acorns in my neighborhood are bitter and require a lot of work.

I collected a bag of acorns from a red oak in the Giant parking lot a block away from my house and experimented with various tannin leaching methods outlined on various websites. In all cases, acorns have to be shelled (of course) before eating. Hitting an acorn with a standard hammer squarely at its pointy tip generally splits the shell in two and makes harvesting the nutty innards (called ‘meat’ or ‘nut meat’) pretty easy.

Boiling was recommended by some and discouraged by others. I tried boiling some of my acorns and don’t recommend this because it takes too long and uses a lot of water and energy (both the kind you pay for and your own). According to Wikipedia, boiling unleached acorns may actually make them “unleachable.”

One website written by a Native American noted a friend who leached her acorns in a cloth sack in the back “clean” part of her toilet. He didn’t recommend this because 1) the tannins stain porcelain and 2) nobody really wants to eat anything processed in a toilet. But should you ever be caught in a drought situation or after an apocalypse or siege with little water and only acorns to eat you know what to do.

I found the following process the easiest and least resource-demanding: 1) put acorns directly into food processor after shelling; 2) pulverize into a meal; 3) leach meal by placing it in a wash cloth and rinsing it repeatedly with hot water (requires that you “milk” the wash cloth, which will be permanently stained) and 4) lightly roast on low heat. Mother Earth News recommends using the heat leftover from cooking something else as it dissipates. This is a good idea because acorn meal is pretty fragile and burns easily.

Acorn meal can be used to make bread and muffins. So I tried the following recipe from the blog GroupRecipes.com. I simplified the recipe a little. The original entry was submitted by “julesong.” They're quite tasty -- the acorns make these muffins (or bread) very hearty.

Ingredients

1 cup acorn meal
1 cup flour
2 tablespoons baking powder
1/2 teaspoon salt
3 tablespoons sugar (I used brown sugar)
1 egg, beaten
1 cup milk
1 tablespoon vegetable oil
2 tablespoons butter, melted

Preparation

1. Preheat your oven to 400 degrees F. Butter a loaf pan.
2. In a large bowl, combine the acorn meal, flour, baking powder, salt, and sugar. Stir well.
3. In a separate bowl, whisk together the egg, milk, and oil, then gradually whisk in the melted butter.
4. To the bowl containing the dry ingredients add the liquid ingredients and stir to combine all,
5. Pour the batter into the prepared loaf pan and bake in 400 degree F oven for 30 minutes.