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Birch Polypore

Edible Edible
Autumn Autumn
Summer Summer

This common white bracket fungus has many uses and has been utilised by humans for thousands of years for its nutritional and medicinal properties.

Mushroom Type
Common Names Birch Polypore (EN), Razor Strop Fungus (EN), Ysgwydd y Fedwen (CY), Gogyrogo (CY), Pniarek Brzozowy (PL), Nyírfa-Tapló (HU)
Scientific Name Fomitopsis betulina
Synonyms Piptoporus betulinus
Season Start Aug
Season End Nov
Average Mushroom height (CM)
Average Cap width (CM) 10-20
Please note that each and every mushroom you come across may vary in appearance to these photos.

Fruiting Body

10-20cm. White turning grey/brown with age. Starting globose then forming a ‘hoof’ shape finally becoming an enlarged flat bracket.


White, very fine pores underneath turning buff with maturity.


White and firm


Growing on dead or damaged Birch trees.

Possible Confusion

This distinctive mushroom is difficult to confuse with any other as it only grows on Birch.

Spore Print

White. Ellipsoid, cylindrical.

Taste / Smell

Mushroomy but a little bitter


Very common.

Other Facts

The Birch Polypore (Fomitopsis betulina), grows on Birch trees and can be a parasite to living trees slowly killing them and then living on the dead tree for many years until the tree has rotted to nothing.
The mushroom grows exclusively on Birch naturally but can be artificially introduced to other types of tree.
It has long been known that the Birch Polypore has medicinal uses, it has been used as a tonic for the immune system, as an antiseptic to clean wounds and promote healing, a plaster that is microporus, antifungal and antiseptic and probably was used by Bronze Age man to get rid of parasitic worms.
In 1991 Austrian hikers in the Tyrol region of the Italian Alps discovered a frozen corpse. When this was later examined it turned out to be a 5300 year old mummy that they named Ötzi. Ötzi had some Birch Polypore on a leather thong around his neck, he also had a parasitic intestinal worm called a Whipworm which can be cured with polyporenic acid which is one of the chemicals present in the Birch Polypore.
Another possible use of the fungus by Bronze Age man was as a very good tinder that can be started with a weak spark or used to transport fire as the fungus can smoulder for a long time and can be used to take to the next camp or destination and get a fire lit quickly without the long and laborious task of lighting a fire by friction.
Birch trees contain betulinic acid which has many health benefits, there are also other chemicals in the Birch Polypore that are beneficial for being healthy. With modern research it is becoming clear that the Birch Polypore is an important mushroom to look into, tests have been carried out and so far found the following.

Antiviral. In tests extracts from the Birch Polypore blocked reproduction in HIV cells, attacked and incapacitated encephalitis infections and has proved positive in treating flu, yellow fever and West Nile flu.

Antibiotic. The Birch Polypore contains the antibiotic piptamine which has been used to treat e-coli.

Anti inflammatory. There are several triterpene acids present and these are known anti-inflammatory substances.

Anti Tumor. Betulinic acid and other chemicals in the fungi have been shown to cause apoptosis, the destruction of cancer cells while not affecting healthy cells.

Antiseptic. For cleaning wounds and being an aid to healing.

Antifungal. This mushroom does not like to share its habitat with other mushrooms and contains some powerful antifungals.

Styptic. The fungus has styptic properties (it staunches bleeding).

The mushroom has very beneficial effects on the immune system and many people drink a tea made from the fresh or dried fungi and swear by its positive effects.
A plaster can be made from the underside of the mushroom, a strip needs to be cut and carefully removed from the pore membrane. This provides a microporus, anti fungal, antiseptic and self sticking plaster, much better than can be purchased from the shops.
A corn or blister plaster can be easily fashioned from the flesh of the mushroom by cutting some flesh into a doughnut shape of the right size and applying to the corn or blister.
The common name Razor Strop Fungus comes from the use in old barber shops of cutting a strip from the underside of the fungus, drying it and sticking it to a piece of flat wood. This was used to give the final finish to the cut throat razors that barbers used. I’m not sure if they were aware of the fact but in doing so they were giving their blades an antiseptic, antifungal and styptic wipe!
The fungus has also been used in the past as very fine emery cloth to polish metals, making ink blotters and even bases for mounting insects for collections.
Truly the Swiss Army knife of mushrooms.


43 comments for Birch Polypore

  1. Michelle says:

    Can I get rid of this in my tree?

    1. Eric Biggane says:

      It is almost impossible to kill the fungus without harming the tree but it is a great medicinal fungus that can be used in a tea for an immune system booster. Birch trees do not live very long, on average, less than 100 years, so if it is getting old, the fungus can’t really do any harm.

  2. Mark Wilson says:

    I am new to mushroom foraging, however I think I have identified a Birch Polypore qhich looks old. Could you help with the id and whether it is edible.
    It has a brown cap with a porous pale underside, it was located on a dead birch tree (I think). When sliced it is white right through..
    Your assistancecwoukd be appreciated.

  3. Alejandrina says:

    Hello my name is Alejandrina thank you so much for the information. I harvested some Piptoporus betulinus and i wonder how much is the dosis I need to take and for how many days ?

  4. Sienna says:

    When is the most Optimal time to harvest for best medicinal benefits and is it possible to dry on a drying rack rather than a dehydrator?

    1. Eric Biggane says:

      The best time is when it looks in good condition, they dry well on racks without a dehydrator.

  5. Bettina says:

    Hello there
    I want to know if i get same benefits from the mushroom by drying and making powder from it?

    1. Eric Biggane says:

      The glutamate concentration goes up if you dry mushrooms giving them have a stronger, more savoury taste.

  6. Bettina says:

    Also how much powder can i put in an capsle or in a smoothie 🥳

    1. Eric Biggane says:

      As it is edible, if a little bitter, it shouldn’t matter how much you consume unless you start eating kilos of them which could cause some gastric problems.

  7. Brian says:

    Im new to foraging but have found some Birch polypore on a dead tree.
    I was tempted to try some. Would I simply cut it and cook the same way as you would mushrooms from the shop? Thanks

    1. Eric Biggane says:

      Although edible it is quite tough and bitter, it is best used to make a medicinal tea than cooked and eaten like other mushrooms.

  8. Tony says:

    I have been trying to find out about making tea from this mushroom. I can’t find any advice about this particular species, but regarding mushrooms in general, I’m coming up against varied opinions on whether I should use boiling water or not. Some even suggest simmering it for 20 minutes. Any ideas?

    1. Eric Biggane says:

      I simply slice the mushroom, place a small handful in a cup and add boiled water about a minute after boiling.

  9. Chris says:

    Hi there, if December is the best time to pick, cut & eat this mushroom when you you say is the time to not pick it as it would not be good for you. Thanks in advance. Chris

    1. Eric Biggane says:

      There is no bad time to harvest this mushroom but December could be a little late as the mushroom may have started to rot by then.

  10. Courtney says:

    I recently collected one apple sized polypore, chopped it into slices and fried them in butter. It was very bitter (like a radicchio) and I found myself hunched over the loo 8 hours later. Other sources will say this is *not an edible* mushroom. It certainly wasn’t an enjoyable experience the way I had them.

    1. Eric Biggane says:

      A small number of people have bad reactions to certain fungus that grow on trees.

  11. Emily B says:

    Hi I got what I was pretty sure was birch polypore and I boiled it up in some water for an hour, about two inches of polypore. But it is not bitter at all, just slightly fruity and tasteless. It was on dead birch but could it be something else? I feel fine hours later after a little sip. I have not quite got my taste back after Covid but is it always very bitter?

    1. Eric Biggane says:

      Looking like Birch Polypore and growing on dead birch, it can’t really be much else. People who have tried it describe it from being tasty and mushroomy to vile and bitter and everything in between. It may be different mushrooms or different palettes or both.

    2. Kimmie says:

      I don’t think it tastes bitter. unless you really steep it too long.

  12. Philip says:

    I slice about 1KG of fresh birch polypore into 5-10 mm thick sections, then place in my one pot on slow cook setting overnight (about 10 hours). You get a very savoury mushroomy (umami) flavoured stock that is great for smoothies and for making savoury dishes like chilli con carne. It keeps for about 2-3 weeks in the fridge.

    1. Stuart says:

      That’s a great idea. Thanks Philip.

  13. İsmet says:

    I have collected nearly 1kg of birch polypore, and not quite sure what to do with, cook? dry? make a tincture? which way of processing do you suggest?

    1. Eric Biggane says:

      Drying them will be the best way to preserve them. Then use as a health tea.

  14. Mikael says:

    I had a quick “taste” of the Birch Polypore mushroom and it left my tongue feeling numb. Is that normal?

    1. Fabio Godinho says:

      It can be very (very) bitter. Numbness itself is not something we have experienced nor would we expect that. You may have a sensitivity to it, assuming it was correctly identified.

  15. John Baxter says:

    Does it have a chemical sort a smell 👃?

    1. Eric Biggane says:

      It does have a smell that could be described as chemical.

  16. George says:

    Came across some real nice BP a few weeks ago. Sliced it into very thin strips and dried on cookie sheets in the sun on a few nice dry days until I was able to have the pieces break and snap when bent. Simmered a few pieces for several hours on the wood stove. I found it to be very bitter but enjoyable. Started with a few ounces to start to make sure no adverse reactions. Tried adding some self made apple mint and ginger peach tea for a very enjoyable drink. Now we keep the pot full on the stove and drink a small glass every day. Also started a few jars of tincture with 2/3 Turkey Tail and 1/3 BP. Plan on letting it soak in the Vodka for about 6 weeks, strain and then simmering the shrooms and combining the two extractions for the final 25% alcohol content mix. Pretty excited about all the good things these fungi have to offer and the thrill of the hunt along with my better half and I have to find them.

  17. sammi says:

    Hi I found what i believe to be a birch polypore on a dead birch tree a few days ago, it is creamy beige on the top and white underneath with lots of pores as one would expect. But the shape is not the classic shape i seem to see everywhere, it is a bit more hoof shaped and the underside does not have the lip, rather its a little more bulbous. I am a new mushroom hunter and I don’t want to make myself ill. could it be anything else? Thanks

    1. Eric Biggane says:

      They can often grow into different shapes and there isn’t really a look-a-like that grows on birch but if you are unsure, you can send photos to [email protected] for ID.

  18. Ellie says:

    As I understand it -the bitter taste is the medicinal part of the Birch polypore, so if you have made a tea and it does not taste bitter you have not extracted the medicinal constituents. I make it up by putting some chopped polypore into a thermos flask and adding boiling water then let steep for an hour or more before drinking approximately quarter to half a cup three times a day. I have found that you can add more water and extract more of the active chemicals, but I would not do more than three washes as it loses potency. I have been using it as an anti- inflammatory and anti viral. I use for a week and then have a break of a week or two and use a different anti inflammatory. (Rosehips, Nettles, Ginger, boswellia) The Pulished Medicals papers have more information about Birch Polypore- when searching use the latin name Fomitopsis betulinus, but be aware that this fungus was previously called Piptoporus betulinus – so try searching for both names. There is also evidence to suggest that an alcohol extraction (tincture) is the most potent form of concentrating the medicinal chemicals in this mushroom.

  19. Bev says:

    Hi all, new to this, I picked some polypore today (Jan 26th 2023) and not sure how or if I can still use them? They are dark brown, a few bigs ones and several smaller ones with quite a spongy underside. Could I make anything out of them or are they now classed as too old?

    Thank you.

    1. Eric Biggane says:

      It’s hard to say without seeing them but I go by smell, if they smell off, they are. If they smell pleasantly of mushroom and haven’t become soft and slimy, they can still be used.

  20. Gundula Azeez says:

    Very interesting article, thanks. I passed a dead, fallen birch tree last weekend, and saw a really weird, very smooth and round whitish thing clinging to the side. It looked like a super-size snail shell. Actually, it looked just like your main picture, but on it’s side … now I know what it was !

    1. Gundula Azeez says:

      Hmm, I’m doubting if it was really on its side, I’m not quite sure now. (Seems odd that a fungus would not know the right way up.)

  21. Rosehip says:

    Always collected birch polypore growing up for the winter, but I never knew all of the official medicinal properties until now. Thank you so much for this free resource!

  22. Sam Kress says:

    I simmer sliced birch polypore on my woodstove and drink two or three cups of it a day for half a week adding more water as needed. The bitterness does not subside so I’m guessing that the medicinal benefits are still there. I’ve been picking them in -5 C and they look and smell as fresh as they do in the summer months.

  23. Aaron says:

    I’ve found plenty of dried up polypore on a tree locally. Is there still benefits if the fungus is in good condition but has dried on the trees already.. all the hard work being done by the looks of it!

    1. Eric Biggane says:

      It should still be fine, just check it doesn’t smell ‘off’.

  24. maria says:

    I had birch polypores growing in my garden and I decided to make a double tincture. Unfortunately (with a small baby) I lost track of time that it was soaked in alcohol and I left it for about 6 months. I continued with the whole process (water extraction) and now have produced an extremely bitter tincture. My question is, is it still safe to take?

    1. Eric Biggane says:

      If the mushrooms were immersed in alcohol for 6 months, they should be safe but I can’t say without being there. Birch Polypores do have a bitter taste.

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