Identifying Boletus Mushrooms

Boletus rubellaA common and easy to identify family of mushrooms, the Boletus family is a large genus of mushrooms which until recently was split into a few smaller families, the main three being; Boletus, Leccinum, and Suillus. With the genome of mushrooms now being sequenced the family has been split much more with the scientific names changing regularly, this can lead to confusion with identification so for the purposes of foraging we consider any mushroom with a stem and pores instead of gills a Bolete.

Almost all members of the larger Boletaceae family have pores or tubes instead of gills which make them an easy family to identify. Boletales also contain some mushrooms without tube-like pores like the Paxillus, Hygrophoropsis and Scleroderma families but this article is about Boletes with tube-like pores instead of gills or internal spores.

Boletes are usually large fleshy mushrooms that come inBoletus purpureus a variety of colours with a thick or bulbous stem and no ring, except for some of the Suillus. The stem often has a network of dark lines or spots. The pores under the cap can be white, cream, yellow, orange or red and are normally easy to remove from the cap.

There are about two hundred and fifty Boletes worldwide with about eighty identified in the UK which, with only a handful to avoid due to toxicity, leaves a good amount of edible mushrooms that can be safely identified for consumption.

For the novice forager there are three rules of identification for edible Boletes that will keep you safe:

Blueing Bolete1. Make sure you have a Bolete, an upright mushroom with a stem and with sponge like pores instead of gills under the cap and growing in soil, not on wood.

2. If there is any red colouring on the mushroom, that includes the stem, pores or cap, avoid as this can be the sign of a toxic Bolete.

3. Slice the mushroom in half vertically, if the flesh turns vivid blue quickly after or immediately on cutting, again avoid due to possible toxicity. The pores on a few edible Boletes can discolour to green or blue but it is the flesh changing colour rapidly that is a sign to avoid the mushroom.

Keeping to the above rules will keep you safe when foraging for Boletes; this does mean that you are missing out on some of the good edible ones but more importantly, avoiding the toxic mushrooms. Boletus edulis, Cep, Penny Bun, Porcini, King BoleteWith a little experience you will get used to identifying this family and as it becomes easier to distinguish between them you will be able to safely identify some of the edibles that don’t stick to the above rules.

There is one mushroom that will pass the above rules of edibility that I don’t recommend eating; it’s not toxic in any way but will ruin any dish it gets into: the Bitter Bolete, Tylopilus felleus. It is one of the most bitter things I have ever tried, the bitter taste lasted for most of the day. It looks quite like the Penny Bun, Boletus edulis, but a small nibble of the mushroom will soon let you know if it is a Cep or Bitter Bolete or if you are a bit worried about nibbling unknown mushrooms the Cep’s stem has a white network of lines on a slightly darker background; the Bitter Bolete has a darker network of lines on a lighter background.

Leccinum scabrum, Brown Birch BoleteThe Cep, Porcini, Penny Bun or King Bolete, Boletus edulis is considered one of the best edible mushrooms, hence the many names and high prices it commands but other Boletes like the Bay Bolete, Boletus badius, the Dark Bolete, Boletus aereus, or the Orange Birch Bolete, Leccinum versipelle, in my mind are every bit as good, just not as well known.

Leccinums generally have less bulbous, white/off-white stems that are covered in woolly black scales giving them a dirty appearance. The Orange Birch Bolete, Leccinum versipelle, is one of the most nutritious fungi growing in the UK with proteins, carbohydrates and fats at a higher level to most other mushrooms, they also contain many minerals and vitamin A and some of the B vitamins. Leccinums should all be well cooked before consumption, a minimum of ten minutes being the often quoted guideline.

Larch Bolete, Suillus grevilleiSuillus mainly have glutinous caps, some have rings on the stem and they all grow in association with conifers. One of the most common and easily identified Suillus is the Slippery Jack, Suillus luteus, it has a ring on the stem and a slimy cap. It is an okay edible mushroom once the slime has been removed but improves in flavour if the pores are also removed and the mushroom sliced and dried. Another very common Suillus is the Larch Bolete, Suillus grevillei, which is odd in that when young it has a white woolly veil or fine cobweb-like mesh covering the pores, a little like a Cortinarius (The Webcap Family of mushrooms). It is best to remove the slimy top and soft pores of Suillus mushrooms as they can cause minor gastric upsets in some people.

Nearly all members of the Boletaceae family have mycorrhizal relationships with trees and can be found under and around both broadleaf and coniferous trees with a few exceptions like the Parasitic Bolete, Parasitic Bolete, Boletus parasiticusBoletus parasiticus, which grows from the Common Earth ball, Scleroderma citrinum, which makes this particular Bolete quite unique.

Some people remove the pores when they find Boletes and spread them about the surrounding area, this will leave behind some spores in the right environment to have a chance of growing into a new mushroom and I will do this with some of the Boletes I find as the pores can become slimy when cooked, but mushrooms like the Penny Bun or Dark Bolete are too good to throw any part of them away and I will eat these mushrooms pores, stem and any maggots included (within reason)!

Most of the Boletes are loved by maggots as well as us humans so I have learnt to share by leaving Red Cracked Bolete, Boletus chrysenteronbehind the really maggot-eaten mushrooms and ignoring the odd few maggots in good specimens, they were born in the mushroom and have only ever eaten mushroom, they taste of mushroom and I’m not prepared to leave behind all the mushrooms I find with maggots in as I would soon end up very hungry indeed. That said the Bay Bolete, Boletus badius, seems not to attract too many flies and can usually be found maggot free.

 

 

23 comments for Identifying Boletus Mushrooms

  1. A.Bullen says:

    Hi. Why great description. But why must it be very well cooked if not toxic ?

    1. Poppy Ives says:

      Some mushrooms are toxic unless cooked, they will only cause gastric upset but who wants that.

    2. John Holland says:

      I’ve been finding a lot of boletes that I thought were cornflower boletes, but though they have cream tops and stain bright blue, they have distinctly pale yellow pores and stem, whereas cornflowers in pictures seem to be fairly uniformly cream.
      Any idea what they are?

      1. Simon Moore says:

        Probably Caloboletus radicans, rooting bolete, rather bitter!

  2. Alex .P says:

    Hi, my Boletus turned a pale shade of greeny blue; is it safe to eat?

    1. Eric Biggane says:

      Without seeing the mushroom I couldn’t say but to stay 100% safe if you are not sure of the species avoid any with red markings or that stain blue when cut. You’ll miss out on some good edibles but also avoid the poisonous ones.

  3. Helmut Frische says:

    Reviewing my last comment and your remarks on boletus mushrooms I find that you DID mention the Bitter Bolete, Tylopilus felleus, sorry, I overlooked this. However my additional observations concerning the degree of pink colour of the pores or tubes of the undersides of the hat may come in useful to some happy frinders of good-looking specimens of Boleto. Better disappointed early than losing the complete meal which might have been so delicious.

  4. Ellen Treon says:

    Found some edible boleros in Charlotte, NC . June 28, 2020

  5. Kieran says:

    I found a boletus mushroom where the flesh of the stem stained blue immediately upon cutting, whereas the flesh of the cap remained pale. When you say to avoid species who’s flesh turns blue, do you mean flesh of stem and cap?

    1. Eric Biggane says:

      If the flesh in the stem or cap turns blue immediately then avoid unless you know your Boletes well enough to make a positive ID.

  6. Eimear Murphy says:

    I believe I have found bay bolete , turns blue instantly. I know they are classed as inedible. Is that because they make you hullucinate or because they would make you ill?

    1. Eric Biggane says:

      Some Boletes that turn blue are good edible mushrooms, the rule of avoiding them is for novice foragers to keep them completely safe and give them confidence before learning some of the individual Boletes. Any toxic Boletes will make you feel ill if consumed, especially if consumed raw. They have no hallucinogenic properties.

  7. Pete Wilson says:

    In a wood i frequent, i recently went a little off track and found literally hundreds of Boletes. They were all
    well past their best with dirty grey caps with yellow undersides. They may even be from last year given their
    condition.I was unable to properly identify them, but was surprised that at this time of year, there were no
    fresh growing ones anywhere, as in places nearby i have found numerous Bay Boletes through late Summer
    and Autumn.

  8. Selina says:

    Hi. I have found some brown bolotes with pale pink stems and yellow tubes. Also pink on cap where holes nibbled. Is pink ok, as opposed to red? When cut it turned very gradually pale blue/green over the course of about 30 mins. So not immediately. Thanks

  9. Ian Dale says:

    Thanks for the link to Caloboletus radicans (September 8 2020). It was not in my mushroom books and I’d been puzzled about what it was. Mystery solved – white Boletus = not edible.

    1. Adam P says:

      Hi,

      Found some boletes yesterday with yellow pores which release dark brown spores, a dark brown cap which peels off to reveal plain white flesh underneath, and a plain white stem. When sliced vertically down the middle the flesh remains mostly white, but with some pink/red staining in the cap. The stems are thicker at the base.

      Would you have any ideas what they might be?

      Thanks!
      A.

      P.S. are there any UK boletes which can be fatal to eat?

      1. Eric Biggane says:

        I can try to ID it for you if you can send in photos of the cap, stem, pores and one cut in half to [email protected].
        The most poisonous Bolete in the UK is the Satans Bolete but there are no reported deaths in the UK, it seems more likely to cause illness but one report from Europe attributes a death to this mushroom, it is more toxic raw.

  10. Chris Smith says:

    I think I have found a Red Mouth Bolete, Boletus Subvelutipes. It has a red stem, bright orange tubes and stains a deep blue when cut. Is this a common bolete and I am guessing I shouldn’t eat it. It is however beautiful to look at.
    Happy to send a photo if it would help ID

  11. Katie says:

    My partner and I picked some ceps and cooked them yesterday (definitely ceps, have picked them before – spongy pores, bulbous white stalk and lovely brown bun-like cap – No red or blue staining flesh).
    My partner is fine but I have been nauseous for the past 24 hours.

    I have two questions,
    first is: how long should you cook ceps for? If you don’t cook them for long enough can they be toxic?
    Second is: Does anyone know if brown-birch ceps are toxic? I have read mixed reviews.

    Thanks

    1. Eric Biggane says:

      Penny Buns can be eaten raw so it doesn’t matter how long they are cooked for.
      I have seen one report from the US where there was a reported reaction when eating one of the brown Leccinums and consuming alcohol but have not heard this in the UK.

  12. Adrian Tupper says:

    Thanks for the good info on this page.

    I have just harvested what I think are two types of birch bolete and a couple of bay boletes. Also an orange capped bolete that didn’t blacken on cooking but was very tasty! Dunno what it was but as it passed your tests I went for it.

    Thanks again.

  13. Xtina says:

    I’d be interested to know about methods of picking the boletes, as I see some people advocate twisting them out of the ground, and others say cut them. Thanks

    1. Eric Biggane says:

      There is controversy over the best method, it is said that picking them could harm the mycelium and leaving an open cut stem could be an easy way in for bacteria. Does anybody have any scientific answers.

Post a Comment

Your email address will not be published. Required fields are marked *