Walking through the forest, most people never realize how much food is growing all around them. Sure, most people know you can tap maple trees for syrup and that you can collect acorns from oak trees. But what about the others?
Birch trees are edible in a number of different ways. Birch trees can be tapped for syrup, and the nutritious sap is used medicinally in Eastern Europe. The early spring buds are aromatic and flavorful if you can catch them before they break bud. But beyond that, the inner bark can be made into a surprisingly nutritious flour, containing with 500 to 600 calories per pound of flour.
Now that I’ve tried it, I found that it tastes quite a bit like buckwheat flour, and it makes delicious cookies.
Traditional Use of Birch Bark
Birch bark flour is made by harvesting the inner bark that carries nutrients from the roots up to the leaves. The outer bark is used to make baskets and buckets, like traditional sap buckets, but the inner bark is the edible part.
Birch bark was traditionally harvested by the Sami people in Northern Sweeden. While some references say that bark bread was a survival food, there’s evidence that it was eaten even in times of plenty.
According to Nordic Food Lab, a group that researches traditional Nordic foods, “There is no indication in our records that historically well-known famine years resulted in more bark being peeled in those years.” They found that it was a staple food source in the 1600’s and 1700’s.
There is some evidence that eating bark flour bread was actually a sign of wealth. “It has also been pointed out that rich Sami families with many tamed reindeer and large milk production normally collected the largest quantities.” That’s because the bark was often mixed with reindeer milk to make the bread.
Even though eating bark flour bread was more connected to wealth than famine, in the 19th century, Swedish officials started a campaign to convince the people that eating bark was dangerous. “Swedish authorities generated intense propaganda against the use of bark for food; and from 1870 onwards Swedish legislation forbade the harvesting of bark from trees growing on crown land.”
Harvesting Birch Bark Ethically
Anytime you cut into the bark of a tree, you’re opening up the trunk of the tree to insects, disease and decay. If you cut around the full circumference of the tree, a practice known as girdling, the supply of nutrients is completely cut off, and the tree will die. So obviously harvesting all the bark from a living tree is not ethical or sustainable, but how much is acceptable?
Some foragers stick to a 1/3 rule, and say to harvest no more than 1/3 of the bark around a tree. Even that is pretty excessive. When rodents damage apple trees in an orchard, stripping them of bark, the farmer won’t even try to bring back anything with more than 1/3 of the bark missing around the circumference. If you’re harvesting 1/3, you’re pushing the limits of that tree’s survival and crippling it for the rest of its life.
Obviously, in a survival situation, you have to do what is necessary to survive, but most of us these days are foraging recreationally and for our own education. In those cases, bark should only be removed from trees that are about to be cut, or trees that have recently come down.
According to the Herbal Academy’s online Botany and Wildcrafting Course, “As a rule, never harvest from the trunk of a living tree. Only harvest bark from a tree that has been recently cut down for some other reason or has recently fallen over on its own. The timing here can be tricky, as you only want to harvest from recently fallen trees (within a few weeks of falling or being cut down) and not those that have begun to rot and decay. Never, absolutely never, cut a tree down simply just to harvest its bark or its root bark. This is not only unethical, but unsustainable, and is the reason why so many tree species used in herbalism, such as slippery elm (Ulmus rubra), are currently at risk from over-harvesting.”
The herbal academy’s course is a great resource for beginning foragers, especially if you’re not sure about best practices for ethical wildcrafting.
The particular tree I’m using was knocked down when a dead tree fell on it in a winter storm. This tree was very much alive and healthy, but natural circumstances brought it down. That makes it the perfect candidate for a wild foraged flour. I didn’t go out and strip a living tree, but I did make use of what nature provided.
How to Make Birch Bark Flour
Start by removing the outer bark. The outer papery birch bark is used to make baskets and containers, and hipsters are using it to decorate their upscale apartments these days. Keep it for another craft project, or fancy up your living room.
I used a box knife to score the outer birch bark and then slipped it under to separate the layers. Once I got it started, it peeled back easily with my hand.
The inner bark is what the tree uses to transport nutrients from the soil to the leaves. It’s actually a little bit thicker than the papery thin outer bark, which you can see from the end of this limb.
Traditionally birch bark is harvested in sections from a living tree, many of ours are small and we’re saving them all for birch syrup. This tree was knocked down when a dead tree fell on it in a winter storm, and it was a few weeks before the weather cleared and snow melted back and I could access it. The inner bark is already a bit dry, and didn’t peel off in sheets like I thought it would.
Perhaps that’s the case with a fresh birch, but I can’t say. None the less, I had a lot of trouble peeling the inner bark with a box knife. I quickly switched to a draw knife and had much better results. It’s tricky to peel just the outer bark, without going into the wood, but with a bit of practice, I got it.
Using a draw knife, the inner bark came off in thin curls, and it was already pretty dry. Likely due to the age of the tree. It had a pleasant, wintergreen scent that filled the air anytime I touched it.
Once you separate the inner bark from the tree, dry it either in the sun, in a dehydrator or near the wood stove. I dried this birch bark in the oven at 250 degrees for 30 minutes.
Once dried, the birch bark is ground into flour. I started with a food processor and after about a minute on high, the bark was mostly flour, with some larger chunks. I transferred the mixture to a stone mortar and pestle and finished grinding up the last bits.
How to Use Birch Bark Flour
Using birch bark flour can be a bit tricky. Yeast cant digest the nutrients in bark flour as readily as they can in wheat flour, and the bread will have trouble rising if there’s too much bark flour. Birch bark flour also doesn’t hold together well in baked goods, so it’s often incorporated in small amounts for flavor and nutrition.
Don’t substitute more than 1/4 to 1/3 bark flour in the total recipe.
Beyond the texture concerns, birch bark flour also has a slightly bitter taste, that is best used in small amounts. Though the raw flour had a strong wintergreen scent, I didn’t taste any wintergreen flavor in the finished baked goods. The bitterness was very mild, and in a blind taste test, I’m not sure I could tell the difference between birch bark flour and buckwheat flour.
Since birch bark bread doesn’t rise well, I decided to use the flour to make birch bark shortbread cookies. Shortbread cookies often have a bit of rice flour incorporated to give them a crumbly texture, since rice flour doesn’t bind like wheat flour. Rice flour usually makes up about 1/4 of the total flour in the mixture, which made for an easy birch bark flour substitution. I found that birch bark flour gave the same result, along with a pleasant earthy flavor.
The final cookies, believe it or not, are absolutely delicious My 3 year old loved them, and actually preferred them to the strawberry banana bread I made that same afternoon, and my baby girl loves banana bread.
They’re crisp and earthy, with just enough sweetness.
Birch Bark Shortbread Cookies
Simple shortbread cookies made with wild foraged birch bark flour.
- 3/4 cup white flour
- 1/4 cup birch bark flour
- 1/4 cup sugar
- 1 pinch sea salt
- 1/2 cup butter softened
Mix the white flour, birch bark flour, sugar and salt together.
Use a hand mixer to blend in the butter until it's fully incorporated.
Give the mixture a few quick kneads until it comes together.
Roll out the cookie dough on a floured surface, and cut out cookies.
Bake for about 15 minutes at 350 degrees.