If you found an especially nice chestnut harvest this year, try making your own gluten-free chestnut flour. Some people call it "the grain that grows on trees." It's easy, gratifying, and very tasty to use in flatbreads, polenta, or pasta.
You will need:
- Serrated knife
- Cutting board
- Cookie sheet
- Spice grinder, food processor, or blender
Where the process starts depends on whether you have chestnuts fresh from the tree or you have chestnuts that are already roasted and peeled. You can skip down the steps as needed.
Making the Flour
Raw nuts from the tree are in spiky shells. You will first remove those and discard them.
Roast and Peel Raw Chestnuts:
- On a cutting board, use a serrated knife to make an X on the flat side of each nut
- Place the scored chestnuts on a cookie sheet. Cutting the peels allows steam to escape from the nuts and prevents them from exploding in the oven.
- Roast the chestnuts in the oven at 400 F for 25 minutes. You’ll notice the skins start to peel back from the X.
- Remove from the oven and allow to cool just enough so you can handle the nuts. The shells and inner skin will come off easily when the nuts are still warm. If they cool down and stiffen up, zap them in the microwave for 30 seconds to reheat and make the skins pliable again.
Dehydrate the Roasted and Peeled Chestnuts:
- Slice whole nuts in half before drying them to speed up the dehydration process.
- Spread your peeled and sliced nuts on a dehydrator sheet and dry at 105 F for 12 to 24 hours. If you don't have a dehydrator, dry them on a cookie sheet in your oven on the lowest possible setting.
- You'll know they're done when the nut pieces are so hard you can't break them in half with your fingers.
Grind the Dehydrated Chestnuts:
- Using a spice grinder, food processor, or blender, grind your dried chestnuts until the flour reaches the degree of fineness you need for your chosen recipe.
- If you're making polenta, stop when the flour has a texture similar to that of cornmeal. If you are making flour, keep grinding until it's super fine.
Chestnut flour should be kept frozen or refrigerated. This way it can be stored for up to six months.
Chestnut flour has a history. Different varieties of chestnuts grow throughout the temperate zone, and many cultures have made use of the nut as a food source. In North America, Indigenous peoples made flour from the dried nuts and ate the whole nuts as vegetables. However, this was before the chestnut blight almost eradicated the native chestnut.
In Europe, chestnut flour was generally considered a famine food—a poor person's substitute for wheat flour. This was not because of taste (it's delicious) but because chestnut flour contains no gluten, which means it doesn't rise. Any bread made with chestnut flour alone will be flat, and apparently, flatbread was under-appreciated in 18th-century Europe.
Chestnuts are high in carbohydrates, low in fats, and have no cholesterol. Try using it in applications, like crepes, polenta, pasta, and pancakes, where you aren't using yeast to have the bread rise. It can also be substituted for up to 20 percent of the regular flour in a recipe to add a light sweetness to baked goods, like chestnut pound cake.