I live smack in the middle of what was once a Garry Oak Grove. Oak trees twine thick above my roof and gnarled branches curl before every window. This fall a literal avalanche of glossy brown acorns fell everywhere, spreading over lawns and side-walks like a veritable carpet. And it was my guilt at their perpetual crunching beneath my feet that inspired this moist, dense, crumbly Acorn cake. With every step I took I could clearly imagine the Lekwungen (who originally occupied this land) shaking their heads in disbelief – how could I trod underfoot such a vital and delicious food? Acorns were once an important food staple, gathered in large woven baskets then steamed and boiled to leach out bitter tannins (more on that later).
But no matter who our ancestors were, they too would probably be struck dumb by this massive food waste. Long before we began to cultivate wheat and grains, acorns were an abundant source of protein, fat and carbohydrates for ancient people around the world from Europe, Russia, and the Middle East to China, to northern Africa.
Today we know acorns also contain large amounts of phosphorus, niacin, potassium, calcium and magnesium – all vitamins and minerals sadly lacking in our modern diets. So faced with the thousands of acorns that lay all around me, I decided this was the year I would finally attempt what had long seemed arduous and intimidating process (I am a lazy cook!) – the making of acorn flour. I’d read about the elaborate and time-consuming processes required, roasting, shelling, leaching, grinding etc – but as it turns out, it wasn’t so bad. In fact it was relatively easy.
I don’t want to downplay the effort, gathering and shelling the nuts took me an hour alone. (And that was only beginning.) The process of leaching out the bitter-tasting tannins took another hour. The Salish were said to place baskets of acorns in running streams for several weeks to accomplish the leaching but I chose the fastest, easiest (though not the most nutritious route to prepare my acorns) – boiling– sacrificing vital enzymes and oils in the process. If you want to know more about modern cold leaching methods, click here.
I then roasted the nuts at (another hour or so) laying them out on cookie sheets and then baking them in the oven. And I was delighted when the house filled with a sweet, earthy, vanilla like aroma. Who knew that acorns could smell so enticing?
Once cooled I ground them in my coffee grinder and came up with 2 cups of a crumbly, mildly sweet, caramel flavored flour. This I baked into a cake which I bravely served up at Gather’s Urban Wilds Food Walk last October. And it was well received, making the hours that went into creation, well, very affirming.
So in response to the many requests for the recipe I received, let me warn you now – this is an entirely home spun creation. I adapted this recipe from several online, so amounts are not exact. I am the type of lazy cook that also likes to ‘improvise’ but that said, there are a few basic guidelines I followed.
Acorns contain tannins, bitter compounds that not only taste bad but can upset tummies. So leaching is a MUST. I’m not going to go on and list all the differing ways to do this – from hot to cold – there are many resources online that explore differing methods, I only want to say that this step cannot be missed – if you want your cake to be edible.
When it comes to baking with acorn flour, it should ideally be mixed with other flours. Wheat, rice, corn, oat – whatever your choice – but remember if you choose a non-gluten flour (and mix with the non-gluten acorn flour) your cake will not rise, and be heavier. Also keep in mind the more acorn flour you use the likelier you will end up with a denser product. I went with a nutritious Einkorn flour, which is the ancient fore-mother of modern wheat, and is described as having a lightly rich, nutty flavor.
Acorns can be stored for up to a year if they are dried out. So if you’re not going to use your nuts right away spread them on cookie sheets and let them sit in a warm oven at the lowest setting for a couple of hours. Acorn flour will also keep for several months if you store it in an airtight container in the refrigerator. The cold temperature prevents rancidity, extending the shelf life. So here we go…
Making Acorn Flour
- Gather a small basket of acorns – about 1 ½ lbs depending on size.
- Make sure the have no cracks or tiny holes (a weevil will have bored its way in). Some foragers advise placing them in a bucket of water and discarding the acorns that float.
- Crack and shell. (Some recipes call for roasting for 10 minutes before shelling as it makes the shells easier to crack and for my second batch of flour I did exactly that.)
- Put the shelled nuts into a large pot of water. Boil for 10 minutes. The water will turn a dark brown. Drain water. Fill pot with water, boil and add acorns and boil again. Repeat this process until water runs clear or until the acorns have lost their tannins (bitter taste). It took me five boils – or approximately an hour of boiling.
- Once you’ve drained your acorn meats, lay them on a cookie sheet for roasting. Place them in a preheated 300 oven until they are dry, slightly crunchy on the outside but moist and fudgey inside – approximately 40 min.
- Once cooled grind the dried acorns in a coffee grinder to a crumbly flour consistency. Keep grinding until you have one cup of acorn flour, lightly packed. Now you are ready to make cake!
Acorn Bundt Cake Serves 8.
- 1 cup cup olive or coconut oi
- 1 cup acorn flour
- 1 cup cake flour or all-purpose wheat flour
- 1 teaspoon baking powder
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- ½ teaspoon ground cardamon
- ½ teaspoon cinnamon
- ¼ teaspoon nutmeg or allspice (or both)
- 6 eggs
- 1 cup honey
- 3/4 cup applesauce
- 1 cup organic cane sugar
- Confectioner’s sugar for dusting
- Butter for greasing pan
- Grease and flour your Bundt Pan
- Preheat oven to 350 degrees.
- Mix the acorn flour, wheat flour, baking soda and powder, sugar, spices and salt in a bowl.
- In another bowl, beat the eggs, oil, honey and applesauce together.
- Mix in the dry ingredients. Pour the batter into the pan.
- Bake 30 – 40 minutes. After 30 minutes, watch for burning, as acorn flour browns faster than chestnut flour. Remove from the oven, let rest 15 minutes, then turn out onto a rack to cool.
- When cool dust with confectioner’s sugar.