Begin by laying out a towel and cracking your acorns open with a hammer (or meat tenderizer) and pulling the nuts out. Discard the shells and any blemished nuts. This is best done outdoors in my opinion.
Raw Acorns have something called tannins in them that are toxic. Tannins are great for dying leathers, fabric, making inks, etc. You can easily extract the tannins by soaking your acorns in water for 5-7 days, this is called the cold process. In the photo above you’ll see the tannins in the left jar after soaking for just one night. The jar on the right has been soaking for 5 days and has been rinsed multiple times. You need to change the water 2-3 times a day using the cold process. I like to keep them beside the sink and refresh the water when I’m buzzing around the kitchen.
NOTE: The hot process involves boiling and is said to leach the tannins in about 30 minutes. I plan to try this method next time.
You’ll know they’re done leaching tannins by simply tasting one of the nuts. If it’s still bitter, soak it longer. If it’s no longer bitter, then it’s time to dry roast them in the oven at about 175° for a few hours until they’re completely dried out. Stirring them on the pan occasionally. Be sure to poke a wooden spoon in the oven door to help the moisture release so that you aren’t steaming your acorns.
Once they’re completely dry, you have a couple of options.
1.) Throw them into a food processor (or coffee grinder) and watch it turn to flour! Store it in a cool, dry place (like your fridge) and use it just like you would flour to make breads, pancakes, cookies, etc.! I suggest mixing it in with your existing flour to add a nice woodsy flavor to your baked goods.
2.) You can toss them in a light coat of cooking oil and seasoning spices of your choice for a nice edible autumn snack, salad topping, or garnish.
NOTE: You can use ANY acorn. But the best and easiest to extract the nuts from (because of their larger size) are the white oak acorns. You can see the difference in the photo. The acorns on the left are white oaks. They're larger than almonds and look delicious!
Acorn Flour is something fairly new to me and it’s certainly not something that I was taught as a young child. But I’ve always been fascinated with acorns and felt disheartened that the beautiful nuts inside were “poisonous”. Well I’m happy to report that, like most wild edible plants, we were misinformed as children. With a little bit of time and patience, these beautiful, meaty nuts can be processed in your kitchen for a delightful woodsy addition to your autumn baking.