If you’ve ever taken a walk through the forest and thought you saw a big lump of mud on a birch tree, you’ve likely seen chaga before. This highly beneficial fungus grows specifically on birch species throughout the Northern hemisphere. It’s been used medicinally for thousands of years, and now you can benefit from it too!
In this article, I’ll give you some hands-on tips about finding, harvesting, and processing chaga. You’ll learn how to identify it, how to harvest it safely, and how to draw the most benefits from this amazing superfood.
What is Chaga, Exactly?
Chaga (Inonotus obliquus) is a parasitic fungus found on birch (Betula) tree species. It looks like a clump of mud or a hunk of charred wood, usually sticking out on one side of a tree.
In certain Canadian regions, the Cree name for this fungus is poashkan or wiskakecakomikih. It has been harvested and used medicinally and spiritually by First Nations peoples here for thousands of years. It’s also been used for both purposes throughout Europe and Asia for about as long!
Chaga is treasured in Russia and Siberia for its numerous health benefits. In fact, Nobel prize-winning Russian author Aleksandr Solzhenitsyn mentioned this healing fungus in his semi-autobiographical book The Cancer Ward.
Solzhenitsyn was writing about his own experience with testicular cancer, and in a chapter entitled “The Cancer in the Birch Tree,” he mentions the odd-looking mushroom, and how he used it to treat himself.
“He could not imagine any greater joy than to go away into the woods for months on end, to break off this chaga, crumble it, boil it up on a campfire, drink it and get well like an animal.”
~Aleksandr Solzhenitsyn, Cancer Ward (1968)
This fungus has been used to treat cancer in Russia for centuries. Interestingly, Solzhenitsyn’s own cancer went into remission shortly after he started taking chaga extract. There’s (super)food for thought!
Chaga contains high quantities of betulinic acid, which is what gives it such potent anti-inflammatory, anti-cancer, and anti-viral properties. This is why we only harvest chaga from birch trees to use medicinally. Although parasitic fungi grow on other tree species, they don’t contain betulin.
How is This Fungus Beneficial?
Well, for one thing, it has amazing antioxidant properties. It’s an immune-regulating adaptogen that’s full of anti-inflammatory terpenes and has extraordinary antioxidant properties too.
If you start looking into chaga’s many benefits, you’ll find yourself down a rabbit hole. This fungus has been used medicinally for thousands of years, and recent studies show that it’s beneficial for countless health issues. Many people use it to treat autoimmune conditions, IBS, diabetes, and arthritis to good effect. Just to name a few.
Other studies show that not only can chaga significantly slow the growth of several different types of cancer cells, it can even cause them to self-destruct! 
In addition to its amazing antioxidant and anti-cancer properties, chaga is remarkably nutrient-dense. This stuff contains a range of B-complex vitamins, copper, selenium, vitamin D, manganese, calcium, iron, zinc, potassium, and magnesium.
As you can imagine, consuming just a bit of chaga daily can significantly increase one’s nutrient intake.
How to Identify Chaga
This fungus only grows in cold climates. You’ll find it on the aforementioned birch species in places like Canada, Russia, Siberia, the Scandinavian countries, Alaska, and North Korea. It grows primarily on yellow and paper birch, which you can identify easily.
Chaga looks like a black, roughly textured lump sticking out the side of a birch tree. Some people mistake birch gnarls for this fungus, but it’s quite easy to differentiate between the two. The gnarls are darkish growths that tend to be smooth on the outside. If you cut into them, you’ll see that they’re beautifully gnarled (!) inside.
In contrast, chaga is always black and rough on the outside, and a beautiful golden hue inside.
Chaga comes in various sizes and shapes, but you’ll know you’ve got the right stuff if it looks like turmeric when you crack it open. As an additional identifier, chaga is usually quite easy to remove from a tree. You might need some elbow grease to pry it off, but gnarls need to be hacked off with a saw.
First and foremost, only harvest chaga from living trees. It’s a parasitic fungus, which means that when the tree dies, it’ll die too. You want fresh chaga that’s humming with health. Although some people recommend harvesting this fungus in wintertime, I don’t.
This is because it’s a lot harder to identify dead trees in winter. If the tree has grown leaves this year, you’re good. You can, of course, harvest it at any time of year. Just know that if you gather it while it’s raining, it’ll take longer to dry.
As mentioned, it’s usually fairly easy to remove chaga free from a tree. That said, although some rare specimens will just fall off into your hands, most need a bit more… encouragement to let go.
Essential Tools and Tricks
When I go foraging for chaga, I take a few essential tools with me. Generally, these include a small hatchet, a chisel, and a bag to carry these items. The bag comes in handy for carrying my harvest home as well.
I use my hatchet for stubborn chaga growths that are below chest level. This allows me to use enough strength and momentum to hack it free. If the chaga is higher up on the tree, I’ll use the chisel instead. I’ll grab a large rock or wooden stump to stand on, as well as a fist-sized rock to drive the chisel.
Then I cut into the chaga where it meets the tree, making small cuts as far as I can reach. That usually loosens it up so I can break it off.
Just make sure that you’re not harvesting from trees that are right next to the highway. Inner cities trees aren’t great options either. You’re going to use this stuff for its immensely healing, immune-enhancing properties, so don’t harvest specimens that have absorbed a ton of urban chemicals from the air and water.
Processing and Storage
Clean the chaga as soon as you bring it home by brushing it thoroughly with a dry, clean paintbrush or toothbrush. This will get rid of any insects or detritus.
Some people remove all the black stuff from chaga and only use the golden inner core medicinally. The research I’ve done implies that the black outer portion is actually the most nutritious part. It appears that this dark layer has the highest antioxidant concentrations! I suggest doing additional research to determine whether you want to use the whole fungus in your preparations or just the inner part.
Regardless of which bits you’d like to use, it’s important to break the chaga into smaller chunks as soon as possible. This stuff dries as hard as a rock, which makes it quite difficult to use later. You can slice it up with a knife, but I just put it into a pillowcase and smack it with a hammer a bunch of times. #aries
Once you break it into 1/2″ to 1″ chunks, lay it out on newspaper in a warm, dry place and leave it there for a couple of months. Turn the pieces occasionally. Some people dry theirs in the oven or dehydrator, but I recommend the natural air-dry method.
After that, you can either store it in airtight jars or grind it into powder with a coffee grinder. I like to do a bit of both. This way, I can add the powder to coffee or toss chunks into soup stock.
How to Use It
Some people add dried chaga powder to their morning coffee or tea. Others pour it into gel capsules. You can also make a potent chaga tincture.
The easiest way is to make a simple tincture via the folk method. Fill a jar 2/3 full of chopped dried chaga flakes or chunks. Then fill the rest of the jar with high-proof alcohol. Everclear (100-proof) is ideal, but vodka is a good alternative. Keep this in a dark cupboard for 6-8 weeks, then strain into a clean jar.
There’s also a double-strength extraction method, but I’ve never tried this one. If you’re interested, check out the tutorial on the Birch Boys website.
If you make bone broth or other types of homemade soup stock, try tossing some chaga chunks in there too. In fact, while you’re at it, try adding a bit of dried reishi and turkey tail as well. These fungi all have a ton of health-boosting properties! You can make every batch of soup an antioxidant-rich powerhouse just by adding a handful of foraged goodness into it.
The usual caveat: you might want to talk to a herbalist or your healthcare practitioner if you’re worried about taking chaga. People with liver issues or autoimmune conditions may have adverse reactions to it. Oh, and if you’re allergic to mushrooms in general, you probably won’t want to try this stuff.
When you’re foraging for chaga, look for specimens that are about the size of an apple. It takes chaga 4-6 years to grow to that size, as this fungus develops very slowly. By harvesting larger pieces, you’ve allowed them to grow to maturity.
Additionally, always leave a chunk behind so it’ll regrow. Advice differs on how much to leave, but I aim for about 20%. This leaves the fungus enough of a “root” to be able to regrow from. Not only is this more considerate and respectful for the chaga, but it’s a bit of selfish altruism as well. If you leave it to regrow, you’ll be able to come back in a few years and re-harvest it.
I don’t know about you, but I try to show honor and respect whenever I harvest anything from the forest. So, along with my hammer and chisels, I usually have something with me that I can use to give something back. In spring and summer, it’s usually a packet of local wildflower seeds that I can scatter. In autumn, I offer nuts and dried fruit for the animals to eat.
If you don’t have anything with you to offer, actions work as well. Like pulling off some creeping ivy from killing a tree, or moving an obstruction in the river, etc. Nature gives us so much, and it doesn’t take much to give a little bit back in turn.
Happy foraging, and enjoy your good health!
- SH Lee et al: Antitumor activity of water extract of a mushroom, Inonotus obliquus, against HT-29 human colon cancer cells. Phytother Res. Apr 15 2009.
- M.J. Chung et al: Anticancer activity of subfractions containing pure compounds of Chaga mushroom (Inonotus obliquus) extract in human cancer cells and in Balbc/c mice bearing Sarcoma-180 cells, The Korean Nutrition Society and the Korean Society of Community Nutrition, Published online June 29, 2010. https://doi.org/10.4162/nrp.2010.4.3.177