The name “chaga” is a borderline buzzword these days. So, I feel it’s safe to assume you’ve either heard it or seen it on the label of some trendy health product.
However, I’ve found that the actual organism is still pretty vague and mysterious to many people. I support its popularity wholeheartedly—it really is a treasure, but stardom can be a double-edged sword. People who personally experience the benefits of this mushroom will hopefully value and therefore steward the mushroom and its habitat. But this rise in popularity is accompanied by rising market value, which often causes reverence to devolve into exploitation. I like to think there’s a happy middle ground we might land on if we keep the chaga mushroom and human health in our sights instead of dollar signs. To do this, we need to be clear about what we’re looking at. “Know your target and beyond,” right?
Chaga Mushroom Identification The chaga mushroom (Inonotus obliquus) is a parasitic fungus found almost exclusively on birch trees throughout the temperate and subarctic regions around the globe. In North America, it’s most commonly found on paper birch, yellow birch, and occasionally on other hardwoods, though I’ve never witnessed it.
This fungi may not have made its way onto your frequently foraged list yet, largely due to chaga's unique form. I walked by it for most of my young life, not recognizing it as a mushroom because it doesn’t have the iconic cap and stem form. Instead, it looks more like a lump of crusty charcoal or a gnarly black burn scar, hence its other names; black mass, birch canker, cinder conk, sterile conk trunk rot, and tinder fungus (it makes an exceptional fire-starting ember).
This black mass that we seek out and harvest isn’t the fruiting body, like most mushrooms we harvest, but a sclerotium—a sterile mass of hyphae that appear years after the fungus has parasitized the heartwood of the tree and long before the fruiting body emerges. The tree can remain alive for up to 80 years with the chaga living inside, and it’s only when the tree succumbs that the fruiting body finally breaks through the bark to shed its spores. Many insects are attracted to this fruiting event, and it’s hypothesized that they may aid in spore dispersal.
The beauty of foraging for chaga, especially this time of year when most other fungi are dormant or subterranean, is that they persist on the tree year-round, making them one of my favorite winter quarries. While I’m hunting snowshoe hares or post-season deer scouting, I’m inevitably scanning the trunks of birches for black masses, which are often easier to spot when capped in fresh snow. I keep a small hatchet and folding saw in my pack just for this purpose.
When I first learned about chaga but wasn’t up to snuff on its life cycle, I would (shamefully) try to just yank them off of the tree or bust them loose with a blow. Often they wouldn’t budge. But sometimes this would result in the whole sclerotium coming off along with a big chunk of bark.
Don’t do this for a few reasons. First, it harms the tree. While yes, the tree is already parasitized and in decline, it’s usually a slow decline, so it likely has many decades left to live. Second, the sclerotium is slow growing but will regenerate if at least 25% is left attached to the tree. I now aim to only harvest from chaga that are larger than a fist. From those, I take a third to half of the mass, not removing any of the tree bark.
How to Make Chaga Mushroom Powder Now you’ve got a crusty, crumbly black mass sitting like a bump on a log on your kitchen counter. It might not look especially edible. First, you need to smash it to bits. You can be as caveman or as French Laundry as you want here, but you’re shooting for a pile of dime- to sand-sized rubble. I like to saw large masses into fist-sized chunks, put those in an old pillowcase, twist it up, lay it on my firewood splitting log, and smash it with a five-pound sledge. You can also use a heavy knife to shave off chunks from the edges inward.
The end product should be a course crumble of both the dark outer layers and the golden interior. These layers contain distinctly different mycochemicals, as well as different flavor profiles, and you want them all. You can air-dry your chaga chunks on screens or in a dehydrator before storying in jars or bags.
Chaga Mushroom Tea If you don’t like mushrooms, don’t worry—there’s nothing mushroomy about chaga. Most people enjoy it as a tea made by boiling the mushroom, yielding a dark, earthy, slightly sweet, toasty, caramel brew. I throw a handful of roughly pounded chaga into a 2-quart pot and keep it simmering on my woodstove. I pull a mug or two off to drink every day and top the pot off with water. The same handful of chaga will keep yielding tea for many, many pots of water.
Sometimes I take it black, with honey, syrup, or cream. Sometimes I add other things that boil well like reishi or turkeytail mushrooms, a cinnamon stick, cardamom pods, sarsaparilla, dandelion, burdock, or ginger. Chaga tea makes a lustrous base liquid for making coffee, chai, even mushroom stock or baking batter. A hot chocolate made with potent chaga tea cures whatever ails me every time.
Chaga Mushroom Benefits I’m not going to make any health claims here, but it’s not for nothing that humans have been using and nearly worshipping this fungus since the 1500s, even dubbing it “the king of herbs.” Conveniently, it’s one of the more researched medicinal mushrooms, and there’s plenty of lab-tested, doctor-approved information regarding its antioxidant capacities, immune-modulating, blood-sugar-lowering, anti-neoplastic, anti-inflammatory, and antimicrobial properties; and perhaps most notably antitumor cancer preventing properties. When it comes to your health, always consult someone you trust, which is especially important for those with pre-existing conditions.
Chaga Mushroom Cultivation If you choose to enjoy this mushroom, know that not all chaga are created equal. This is where things get tricky. Historically, folks have collected chaga from the wild, and this is where all of our anecdotal and scientific information about its health-bolstering abilities. But since its popularity spiked, it’s now being cultivated too.
Some people now grow chaga by inoculating birch trees. While these mushrooms have similar mycochemical levels as their wildcrafted kin, there are also lab-grown specimens saturating the marketplace grown on sterile substrates like rye or sawdust. From what I understand, these mushrooms do not have the same chemical makeup.
It turns out that many of the properties we seek out in chaga actually come from birch trees by way of the fungus. Maybe you've heard that we are what we eat, but we're even more of whatever our food has been eating. Sterile substrate doesn’t quite cut it. Through this lens, wild foraged chaga is the best choice, but due to market demands, wild chaga is being harvested rapidly, with little regard for the future and populations may not keep up. This leaves us chaga consumers in a pickle.
My current feeling, which will inevitably change as I learn more, is that if you’re able, collect your own and only collect what you need for yourself and your family. If you’re not able to harvest your own, purchase it from a forager you trust or from people who grow their chaga on living birch trees. There are some really interesting models of growing chaga in tandem with managing birch-dominant woodlots for firewood and paperwood. If you have access to birch trees, maybe try growing your own.
Despite this tug of war, I do hope you go out and discover the joy in finding chaga and then the joy in tasting it. It's popular not just because it’s good for us, but probably more because it’s just plain delicious.