Bay Nature

How to Make Acorn Bread from Scratch (and Decolonize Your Diet a Bit)

Karuk food writer explains how to get started with gathering and cooking with wild foods in this acorn bread recipe

October 12, 2023

Editor’s note

Karuk food writer and cookbook author Sara Calvosa Olson wants to help us decolonize our diets—but she doesn’t think we have to do it in one fell swoop. It isn’t always easy to find wild food, or to know what to do with it. “Think of this as sort of a reverse cookbook,” she writes, in the beginning of her newly released cookbook, Chími Nu’am: Native California Foodways for the Contemporary Kitchen (Heyday, 2023), which is intended for those new to gathering wild foods. “It isn’t the type of book in which you find a recipe and then run to the store for the ingredients you need to fulfill your weeknight dinner grind. This book requires a connection to nature and food gathering that you will need to nurture, to become inspired by your role as an environmental steward.” But she doesn’t mind if you use a few store-bought substitutes to get started.

In Bay Nature’s Fall 2023 issue, Olson, who grew up near the Trinity River in northern California and now lives in the Bay Area, writes about a quintessential fall mushroom—the matsutake (also known as xayviish in Karuk). With that essay, she includes a recipe, Mushrooms and Mussels on Acorn Bread. Now, in the spirit of Olson’s approach, you can substitute a crusty brown bread, or even bake the bread with some commercial acorn flour from a Korean market. But if you really want to connect with the oak woodlands and savannahs around us in the Bay Area in a new way—try starting from scratch. By picking up some acorns.

Here, in an excerpt from Chími Nu’am—which means “Let’s eat!” in KarukOlson walks us through the labor of love that is acorn processing, from collecting the nuts to baking your own bread. The cookbook has lots of creative recipes for acorn flour (crackers! Pie crust! Acorn miso rub for meat!) and is available through Heyday.

Kate Golden, digital editor

How to make acorn flour

Acorns are a cornerstone staple food for most Native communities. The nuts from the oak tree, all acorns are edible with the proper processing. There are two methods for processing acorns: cold leaching and hot leaching. A cold leaching process takes much longer but offers more versatility when using the flour. It also preserves the nutrients. I don’t teach hot leaching because I prefer to maintain the acorn’s nutritional value. There is a reason most tribes would leach their acorns in cold water and then cook the meal in baskets with hot basalt stones until thick and bubbling: It is the most nutritious way and, as long as it’s been leached well, it’s delicious, whether you like it with frogs (lumps) or not.

Cold leaching method

What you’ll need: an acorn-collecting bucket, a blender, a large jar (2 to 21⁄2 liters) with an airtight lid, cheesecloth, a fine-mesh sieve, bowls, a nutcracker, a chestnut knife, a dehydrator

The short answer to how to make acorn flour 

(for people who have made acorn flour and just need to remember the order of the steps)

  •  Gather up a bunch of acorns in a basket and let them dry for a couple of days inside the house near a stove or sunny place, in a single layer to prevent mildew. Moisture is the enemy of your acorns.
  • Crack the acorns with a nutcracker, hammer, or stone.
  • Peel or rub the red or brown flaky testa (seed coat) from the acorn.
  • Put all the peeled acorns into a blender with an equal amount of water and blend into something that looks like a milkshake.
  • Pour the “milkshake” into a jar, screw the lid on, and place it in the refrigerator.
  • Pour off the yellow tannin water each day, add new water, and shake it up. Do this until the meal is no longer bitter.
  • Place the acorn meal in some cheesecloth and squeeze out all the liquid acorn milk into a bowl.
  • Put the acorn meal in a food dehydrator, using the fruit leather trays or parch- ment, at 115°F until it’s crispy and dry.
  • Put the crispy dry acorn meal back into the blender and whiz it into flour.

The long answer to how to make acorn flour

The season change will bring those first breezes, which will knock the first batch of acorns from the tree. Those nuts often bear a tiny little borehole from a moth, and though you can technically eat the growing little grub inside, I won’t blame you if you’re not feeling that decolonized yet. You can gather up these acorns for the burn pile to cut back on the number of infected acorns next year. Or, if you have very few infested acorns, the little grub is good protein for wildlife if you have a robust population of animal relatives that feast in your yard. It’s the second drop of acorns we are after. Collect a bucketful of acorns. The size of the bucket is up to you. Sort out all the acorns that have holes or visible mildew.

Lay your acorns out in the sun in a single layer, or near a stove or sunny place in your house to dry out. It will be much easier to remove their hats and outer hulls if the acorns have had a chance to dry a bit. You also want to prevent your acorns from mildewing by keeping them very dry—the area near a woodstove is a pretty great environment to keep a basket of acorns. When you’re ready to make flour, you’ll need to break out a hammer or a walnut cracker, and I recommend using a chestnut knife to do the detail work.

Crack the acorns and remove the outer hull. Depending upon your acorn, there is usually a bit of papery membrane, called the testa, between the shell and the nut.

The cold leaching process for acorn flour. (Sara Calvosa Olson)

I use the chestnut knife to get into the grooves and remove the membrane. It’s con- sidered polite to clean your acorns well, as it demonstrates hospitality and a deep caring for your guests. Hospitality is an underrated art—it can be a deep practice of empathy and service down to the smallest detail. However, the testa is fine to eat, so don’t sweat it too much. You can also use your chestnut knife to clean up any spots. I like to fill up a jar of water and toss my cleaned acorns into the water as I’m working, to keep them until I’m ready for the next step. It soaks them to remove any dirt. Pour this water out before the next step.

Once the testa has been removed, place a batch of acorns into your blender. Add a few cups of water and blend until fine. Place the ground acorn and water mixture from the blender into a large jar and fill the jar up the rest of the way with more cold water, until it’s about half water, half acorn. Close the lid and store in the refrigerator. Each day, pour off the water, filtering through a piece of cheesecloth, and replacing the yellow tannin water with clean, cool fresh water. Replace the lid on the jar and shake it up before returning it to the refrigerator. Different acorns have different levels of tannins so you may need to do this for several days or even several weeks. Taste the ground acorn after a few days and see if the bitterness has leached away. If not, keep going for a few more days.

When the ground acorn is no longer bitter, and you’re ready to make some flour, place a large piece of cheesecloth into a colander, letting it hang over the sides, and place the colander into or over a bowl.

Pour everything from the jar into the cheesecloth filter. Pull up the sides of the cheesecloth and twist and squeeze all of the water out of the acorn meal and into the bowl. Save the acorn milk! You can use it to make freezer pops (page 208) or smoothie bowls (page 188) or to add to ground peppernuts for cocoa (page 106), or to just drink it. The cheesecloth will catch all your acorn meal and you’ll have a big wet ball the consistency of clay. At this point you can use it to make acorn soup or you can dry it for flour.

Acorn flour after being processed. (Sara Calvosa Olson)

To dry it for flour, spread the wet acorn meal out on the fruit leather trays of your food dehydrator, or use parchment if you just have the regular trays. Turn the dehydrator on to 115°F overnight. After 8 to 12 hours, check it to see if the acorn meal is dry. Once it’s completely devoid of any moisture, pull it out to cool. Do not put it straight into a jar or it will get moist again. Once it’s completely cool, you can put the acorn meal into a blender and whiz it into flour or keep it in this form to store in a cool dry place. Acorns can last a long time, but I recommend using the flour within a year.


Rustic Acorn Bread

Sliced acorn bread served with butter and a bowl of mushrooms. (Sara Calvosa Olson)

Serves 4. 

I wanted to make a nice sturdy loaf without the denseness of a full acorn flour bread, so I mixed this with bread flour. Fennel pollen is not for everybody, but I love this savory floral aromatic. It reminds me of Italian sausage. It grows everywhere, it’s not endangered in any way (it’s an invasive import from Italy), and you have very little chance of stepping on anybody’s toes in a fennel patch. Put it on your gathering list for late summer or early fall! This would be a great spice to trade for other ingredients. as it’s rather expensive to purchase and can be difficult to find in stores.

2 cups bread flour, plus extra for dusting the work surface

1 cup acorn flour

11⁄2 teaspoons active dry yeast

1 teaspoon maple sugar 1 teaspoon fennel pollen

11⁄2 cups warm water (slightly warmer than room temp)

In a medium bowl, mix together the bread flour, acorn flour, yeast, maple sugar, and fennel pollen.

Add the warmed water to the dry ingredients and combine to form a sticky wet dough ball. Cover the bowl with plastic wrap or a kitchen towel and set aside for 12 hours.

Turn the risen dough out onto a lightly floured piece of parchment paper and gently knead and fold into a cohesive ball; you don’t want to punch out all the air bubbles. Once it’s a ball, set it in a parchment- lined bowl for 1 hour.

Preheat the oven to 425°F, and place a Dutch oven with a lid into the oven to heat for 30 minutes.

Pull the Dutch oven out of the oven. Carefully lift up the parchment containing your dough ball and place it, paper and all, into the Dutch oven and cover with the lid.

Bake for 30 minutes, then remove lid and bake for 40 more minutes. I use a chopstick or skewer inserted into the center of the loaf to check for doneness. If it comes out clean, the bread is done.

Use the parchment to lift the bread out of the Dutch oven and allow the loaf to cool on a rack.

This article, recipe and photos are excerpted from Chími Nu’am: Native California Foodways for the Contemporary Kitchen by Sara Calvosa Olson. Reprinted with permission from Heyday © 2023.

About the Author

Sara Calvosa Olson (Karuk) is a food writer and editor living in the Bay Area with her husband and two teenage sons. Her work dwells at the intersection of storytelling, Indigenous food systems, security, sovereignty, reconnection, and recipe development. Reflecting an interest in both culturally sound and faithfully updated techniques using traditional Indigenous plants and animals, her cooking inspires a new look at the oldest foods in California. Visit her website at, and follow her on Instagram at @TheFrybreadRiot.

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