Once every few years I'll go out in the Winter to enjoy the birch trees and gather some chaga mushrooms for tea. Mostly as an excuse to go on a winter hike and enjoy some fresh air. Today I'll share a few of my opinions on the topic, as well as some newer information that might make some think twice about drinking it at all.

I've been harvesting Chaga (Innonotus obliquus) for around 15 years now and it was one of the first wild mushrooms I picked from a guide and studied the habitat to understand it. Drinking it is purely a novelty for me.
I don't take it for health benefits, and I feel medicinal mushrooms are often co-opted by people selling things with greatly over-exaggerated claims.
When to Harvest Chaga
Chaga looks like a dark, asymmetrical black mass growing from birch trees easily confused with burls or even cherry knot fungus by some. I harvest it in the winter as it's easier to see after the leaves have fallen. I may harvest some every 3-4 years. I occasionally make a batch of tea if I feel a cold coming.
Here's a few tips on harvesting:
- Only harvest chaga from living birch trees. Mushrooms taken from dead trees have died and tea made from them tastes like drinking a glass of mold.
- You'll need a hammer and a chisel to remove it from the tree.
- Practice sustainable wild crafting. Take only what you need, and you don't need a lot. Drunk occasionally, one pound of chaga lasts me multiple years.
- Know your local regulations as it may be illegal to harvest from State Land.
I asked my friend and author of the book Untamed Mushrooms Michael Karns his opinions on when the mushrooms should be harvested which I thought were logical. Here's what he said:
"The assumption is that the beneficial compound in Chaga (aside from various polysaccharides like inotodial, ergesterol peroxide) is betulinic acid. Betulinic acid comes from the name Betula, which is the scientific name for birch trees...The tree goes dormant during winter and the hypothesis is that the betulinic acid is concentrated in the sclerotic growth during the dormancy".
If that's true or not I can't say, but I think sharing the hypothesis, at the very least can help persuade people to only harvest it during the winter to help promote sustainability.
How to Prepare Chaga for Tea
After the mushrooms are harvested they need to be cleaned, then broken down into pieces using a hammer and chisel.
I do this in a garage as the crumbly, outer black surface creates debris during processing.
Next the mushrooms are put on a dehydrator tray. Dry the chaga at 100 F for 24 hours or until bone dry.
Store the dried mushrooms in a glass jar in a cool dry place until you need them and they'll last for years.
Chaga powder, in my opinion, is a waste of chaga, for a number of reasons. First, and most importantly, grinding the mushrooms to powder results in a single use. Chunks of chaga can be re-used multiple times (at least 2-3) without a noticeable loss in flavor.
Secondly, the ground mushroom powder is extremely fine. It's so fine, that even strained through a coffee filter there will be small, near imperceptible debris that add tannins and a slightly unpleasant, granular texture I can taste.
How to Brew Chaga Tea from Chunks
While most teas that are an infusion of boiling water, chaga is a decoction, or a long-simmered infusion. The mushroom pieces are combined with water (roughly 8 cups per ½ oz chunk) and cooked for at least 30 minutes or until the water is dark like black tea.
After the tea is made, the chunks can and should be re-used. I put the used chunk in a jar in the fridge until I need it.
To make additional batches, I combine the used mushroom chunk with more water and cook it again, repeating the process until the mushroom's spent, at least two to 3 times.
The book Medicinal Mushrooms: The Human Clinical Trials also discusses traditional methods of fermenting the decoction for extraction of compounds by indigenous healers in Siberia. They compare the benefits as you might contrast sauerkraut and cabbage.
What Does Chaga Tea Taste Like?
In short, it's near flavorless. It has a subtle, woodsy aroma reminiscent of very mild tea. Give it to someone unfamiliar with it and they may say it tastes like nothing, or that it tastes like tree bark.
If cooked for a longer period of time the color gets darker and develops a slightly stronger flavor, but it will never taste as strong as, say, regular black tea.
Side Effects
There's lot's of flowery information online extolling Chaga's health benefits, that it cures cancer, and plenty of other claims, but not much on the side effects. The most recent writing I've read on it is the book Medicinal Mushrooms: The Human Trials.
The studies quoted to support the medicinal proclamations of the mushroom are typically from Russia and over 40-60 years old. None of the studies were randomized, placebo based, controlled or blinded.
What we do know about chaga now is that there's definitely other side effects tool. I had a diabetic girlfriend who couldn't drink it for blood sugar issues. Chaga doesn't contain caffeine, but It has stimulant properties that keep me up at night if I drink it before bed.
Here's some good examples of problematic reactions to chaga from Medicinal Mushrooms:
- Caution against large or prolonged ingestion as a recreational beverage due to oxalate content. Simmering chaga for 2-4 hours will increase the extraction of oxalates
- Paul Kroeger, a mycologist from Vancouver, recorded 9 cases of adverse reactions chaga products.
- A 72 year old woman with cancer took 4-5 teaspoons (of powder) daily for six months, suffering liver damage and irreversible kidney failure from oxalates.
- It should not be taken two weeks before surgery.
- Avoid if taking blood thinners. There are multiple reports of entire mucous membranes sloughing off in those taking blood thinners.
- High oxalate content could cause issues with osteoporosis.
- Diabetics should probably avoid it.
More Wild Beverages
How to Make Chaga Tea
Equipment
- 1 4 quart soup pot with lid
Ingredients
- ½ oz dried chaga mushroom fresh can also be used
- 8 cups water or filtered water
Instructions
Make the Tea
- Combine the chaga and water in a pot, cover and bring to a simmer.
- Turn the heat to as low as possible and cook for at least 30 minutes or longer for a stronger flavor.
- Remove the mushroom, put in a jar and store in the refrigerator to make additional batches of tea.
Additional Batches
- Reuse the mushroom until it no longer makes tea. 2-4 infusions can typically be made from one chunk. For a stronger brew, cut the water in half or simmer uncovered until the tea develops a dark color.
Mary Horsman
Can you safely drink two cups of chaga tea a day....or is that too much. I made tea by using chaga and my slow cooker?
Alan Bergo
Sure you can, but I don't drink it every day of the year. Back when I was working as a line cook I would make it for the whole staff on a daily basis. We would drink gallons between 3 or 4 people. When the pot ran dry, I'd make another gallon. After a few weeks the novelty would wear off and I'd forget about it for a while, then we'd repeat the cycle. Moderation in all things.
Zack
I understand that you say cook. But as in preparing other teas water temp is also important. So, I am inquiring is it a simmer, a boil or a particular temp range to hold for the 30 minute cooking process?
Alan Bergo
Hey Zack! I use the lowest heat possible to limit evaporation.
Darcie Clark
Thanks for the recipe. Is the amount of chaga the same if you use powder instead of chunks?
Much appreciated!
Alan Bergo
Hi Darcy. Yes the amount is the same.
Thea
Alan,
This is the most thorough, balanced, prudent explanation of chaga that I’ve ever found. It’s so easy to get swept up in pseudo-scientific hype and alternative remedy overload. Your article helped me feel more informed and more validated in my skepticism of the mushroom madness in which chaga is but one natural resource being hyped. Nature provides infinite riches. It’s up to us to choose what to trust, and responsibly consume.
Alan Bergo
Thanks Thea. It was a fun one to put together.
Nicki Schneider
Thanks for sharing!
I enjoy chaga tea in the winter from time to time, but prefer to combine it with burdock root when decocting.
I'm also known to add whatever coffee is left in the pot from the morning and sweeten with a splash of maple syrup.
Alan Bergo
Thanks Nicki.
Pete Hautman
A recent post on one of the FB mushroom groups showed a pic of some random fungus with the comment, “Anybody know what this is? It looks medicinal.”
IMO, that pretty much sums up the pop science mindset, especially where mushrooms are concerned. I appreciate your skeptical (but not closed-minded) perspective.
Regarding chaga’s effect on blood glucose: I’ve been a type-one diabetic for 40 years. I’ve tried chaga tea a few times (mostly out of politeness, because someone else has prepared it) and never noticed it affecting my glucose levels. It would be interesting to see a controlled study of that. Next time I have some chaga I’ll keep a closer eye on my glucose numbers.
Alan Bergo
Thanks Pete, I feel the same.
Beth
I have been using Chaga and giving it to my parents (who are 91) and who drink it regularly for over a decade. I have always collected it in the winter and prepared it the way you show. I tried the powder and after destroying a coffee grinder decided that wasn’t for me—I chose the lazier way. I have noticed that Chaga makes me generally feel better, with more energy, however too much of it and it decreases my appetite (for me not a great thing as I am borderline underweight) and also makes me extremely hot. So you may want to avoid if you are menopausal! For these reasons I tend to limit myself to 1-2 cups a day. My parents generally do the same. I think it has been beneficial for both of them, but mainly they love the taste and it’s a good alternative to cofffee or tea. We all keep a pot going for days, often with a slice of ginger added and occasionally some honey. When it’s done we put it in the vegetable garden.
I once found Chaga on a sugar maple, which think is quite rare and I suspect the Chaga may not be the same chemical make-up as the ones I find on yellow birch.
As with most things I think moderation is key.
Thanks for the great commmentary and alternate perspective on Chaga.
Alan Bergo
Thanks Beth.
Tina Nebergall
Thank you for this informative article Alan. It is good To read about some of the possible contraindications. After going through stage 3 colorectal cancer treatment last year,
I was inundated by well-meaning people telling me all kinds of things that I should take and do that would be good for my health. As a fairly knowledgeable herbalist and forager myself, I took a lot of their well-meaning advice with a grain of salt. There's a lot of things out there that are not clearly researched. I chose to be very conservative taking additional supplements, due to the fact that I was on chemotherapy. I developed an allergy to something that took a while to figure out.
It ended up, I was allergic to one of the chemotherapy agents and had a super scary reaction during treatment. Taking the conservative path of what I added to the mix of treatment was helpful in my case. There just is not enough information as to how different things can things can affect different people when mixed together in the human body. It is good to question everything.
Alan Bergo
Agreed. Glad you're doing good Tina, thanks for commenting.
Jasmine
Thank you for bringing an evidence-forward voice to this medicinal foraging topic.
Alan Bergo
Thanks Jasmine. I'm sure it'll be a ride. I get tired of seeing all the benefits sold to people, in more ways than one.
E. BLACK
I enjoyed your article and cautions. Most if all i love your wooden cup.Are they available ?
Alan Bergo
Hi E. Yes, it's called a kuksa. I know them as being Finnish. They're lots of styles and price ranges. Good for outdoor cooking and I'm birch should be the traditional wood they're from, if I'm not mistaken. I put a link to it on the picture at the beginning of the post.
Gilbert
By searching >chaga pubmed< you can easily review scientific studies on the subject. I saw at least 4 dated 2023. One linked below.
A native American claims chaga cured him and others of diabetes. Don't scoff. You will find evidence it's effective to reduce insulin resistance. Pharma Pimps would caution against its use because continuing insulin or other drugs without compensating could cause problems. Oxalic acid content? Of course that suggests an upper limit on consumption. As Paracelsus identified 500 years ago, dose, host, timing and combinations make a poison or a cure.
I only use powder, a teaspoon or less per cup or pint. It is pleasantly bitter, like coffee.
Bang the chaga with a blunt hammer\tool. It will fall off. No cutting needed.
BTW willow bracket a hoof fungus is similar in content and taste. Its use in Asia is well documented, too.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10728660/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6173430/
Alan Bergo
To play devils advocate, I'd point out none of these links are to clinical studies. Even peer reviewed essays have come under fire recently and I always try to dig below the surface a bit.
Gilbert
That's a high standard. But clinical studies give at best statistical results which apply to populations, not individuals. Typically there's a distribution of outcomes. Each person should use their own estimate of risk and benefits.
Alan Bergo
Agreed. I just think it's good to have a healthy dose of skepticism. I encourage people to find the balance between Western medicine and traditional folk remedies as I think both have benefits.
Mark
Its worth noting those “high standards” are exactly how drugs get approved in the first place; it isnt sufficient to say “they do good things in cell culture” and if it was, your beloved pharma pimps would not be failing to bring tens if not hundreds of drugs to market for every one that succeeds….as it stands that level of rigor is why so few drugs make it to fda approval, and rightfully so.
Not sure why chaga should get a pass on the same general gatekeeping, other than romanticized bias….
Mark
Alan said he saw few STUDIES since 2020, You cited a review article (and a weirdly hyperbolic one for publication in a mid-tier scientific journal), which is not at all the same thing.
It did cite multiple studies, but as alan said, they tended to be mechanistic. There are thousands of cellular interferon inhibitors, for example…less than ten have become fda-approved cancer therapeutics, largely due to off-target effects, issues w metabolism and achieving physiologically, relevant concentrations in the body, etc. that meant that they were still ineffective at treating actual cancer in actual people. I was in grad school when aspirin was actually being looked at hard as a chemo adjuvant, because it appeared to inhibit a multidrug antiport channel overexpressed in many tumors… problem is, what it did in a petri dish it didnt do in people, unless given in toxic doses due to blood thinning and other side effects…. The list goes on. Thats why science takes time, and looks at multiple steps and variables.
I don’t care if anyone does or doesn’t take Chaga, but it would be nice if more people understood more science
Kevin L Wilson
I'll put this to rest my son is a stage 4 medulloblastoma brain cancer survivor of 10yrs after the fact that he went through all the traditional poisoning before an uncle told me about chaga, his cancer at the time after the chemo and targeted radiation and stem cell transplant all failed was throughout his spine and brain a month and a half of Mr giving him chaga he was clean. I continue to give it to him throughout the week 3 days one week and 4 days the following absolutely NO SIDE EFFECTS. These individuals who come out saying they're bad things on this mushroom are jealous because they're not getting paid their chemo bonus checks.
Bryanna Keseloff
The first study isn't even a study, but a general overview of it's history ect. with a way overblown significance tacked onto said details and making way too many assumptions that aren't tested, and the second study isn't even on chaga, but a completely different species! I really wish classes on how to actually read and decipher scientific studies were required in school. Society needs it. Bad.
Whitney
Thanks for sharing. I love reading different uses for chaga. This is exactly how I used to drink chaga. I’ve been drinking chaga for 7 years and went deeper into its medicinal properties. I only harvest in winter, not just for what Mr. Bergo mentioned, but because it’s better for the tree as well. I powder it. It helps break down all the cellular properties for our bodies to access. I never boil. Boiling can help open up the mushroom’s cells, but it can also kill beneficial properties. What you want out of the mushroom should determine how you prepare it! 🙂 I steep 1/2 tsp overnight in a tea ball in my coffee pot. I leave the tea ball in until the pot is empty. I pour over a filter into my cup every morning to get out the fine particles. They are dangerous as mentioned in his article. This is why I do not agree with the commercially sold instant “Mushroom Coffees.” I add ginger, cinnamon and almond milk for flavor. One pot lasts me about 5 days. I always throw out by the 7th day. I compost the mushroom powder from my teaball. Chaga is a daily part of my life. It’s helped with inflammation, circulation and I haven’t had a return of cancerous cells. I believe its an amazing preventative. Not a cure-all and should be prepared with respect. It can take up to 20 years for a tree to grow.
Alan Bergo
Thanks for chiming in Whitney.
Gilbert
Chaga was known to Native Americans before the current fads.
If I can copy a link and the chaga entry:
Medicinal plants used by the Aboriginal people of boreal Canada. Plants are sorted by scientific name. For each plant, family name, growth habit, vernacular name(s), part(s) used, use(s), and reference(s) are provided.
Click here for file(1.1M, DOC)
Inonotus obliquus (Ach. Ex Pers.) Pil.
Hymenochaetaceae, Fungi
tinder fungus (Eng.); polypore oblique (Fr.); pōsākan, wīsakīchak omīkī, wīsakecak omikīh (Cree)
Decoction drunk to treat heart conditions or mixed with other plants in a medicinal tea for high blood pressure. Soaked overnight and given to help an underweight child gain weight [Cree: 13]. Placed on the skin and burned to produce a counter-irritation in the treatment of arthritis [Cree: 95].
The parent article\study:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3316145/
Sam Holmgren
Alan- This is excellent content. As a novice forager and amateur in the kitchen, I’m in search of interesting flavors, so harvesting Chaga isn’t a high priority. Also it is refreshing to get the skepticism instead of cheerleading on the “benefits” of consumption. Thanks for sharing your insights.
Alan Bergo
Thanks Sam. Yes it's been on my mind for a while to share. All we really see is cheerleading, and it's mostly from people selling it.
Irina Peters
Thanks. Allan! I have been putting off gathering information on medicinal mushrooms for when I have more time, but was sceptical about the claims as well. I have read something about the traditional use and research in Russia when I first heard about it, and wondered about the quality of it, concerned about my ageing friends who are using any Chaga looking conks for ailments, while being scared to see a doctor, in case they have cancer!
Alan Bergo
Thanks Irina.
Gilbert
>In preclinical studies, chaga showed antitumor (12) (13), anti-mutagenic (9), antiviral (14), antiplatelet (2), antidiabetic (15), antioxidant (8), analgesic (3), immunomodulating (16), anti-inflammatory and pain-relieving (3) (19), anti-allergic (17), cognition-enhancing, and antioxidant effects (18). Oral administration of polysaccharides from chaga increased exercise endurance and biological measures related to fatigue (20) and may also have antidiabetic effects (4) (27).
In addition, chaga extracts and its constituents showed inhibitory and pro-apoptotic effects against colon (5) (21) (22), lung (28) and liver cancer (1) cells, and the active constituent Inotodiol exhibited antitumor activity against cervical cancer cells (23). Chaga has also been shown to induce selective apoptosis in tumor cells without impacting healthy cells (1), and inhibited melanoma in a murine model (7).
https://www.mskcc.org/cancer-care/integrative-medicine/herbs/chaga-mushroom
Alan Bergo
Thanks for chiming in.
Marena Markel
Hello, haven't tried recipe because I felt your information was very knowledgeable and therefore it is not the tea for me. But I wanted to make note that your presentation of said information was excellent and visually enjoyed too
Alan Bergo
Thanks Marena.