Boletus Edulis: The Ultimate Mushroom Guide

About The Boletus Edulis Mushroom

King Bolete is a very popular, delicious, meaty mushroom that grows all over the world. The king bolete (Boletus edulis), also called penny bun, ceps or porcini, is a popular edible mushroom native to Europe. The “king bolete” name also applies to several very similar, and also edible, North American mushrooms, but these appear to be different species.

King boletes are large, stocky mushrooms with pores, rather than gills—they are quite typical boletes, being the officially designated type species of the genus. They (and their North American look-alikes) are prized by mushroom-eating enthusiasts and have been used in folk medicine to treat a variety of complaints, including lumbago and tendon problems.

Sometimes this mushroom is difficult to find because it barely pokes its cap above the soil surface. Its elusiveness is compounded by the fact that sometimes it does not even push above the needles that have accumulated on the floor of the forest. Experienced mushroom hunters look for small "humps" in the litter that indicate these choice mushrooms are hiding underneath.

Boletus Edulis in other languages:

1. Porcini – Italian

2. Cѐpe – French

3. Rodellon – Spanish

4. Steinpilz – German

5. Penny bun – UK English

6. Borowitz – Ukrainian

7. Hrib – Czech

8. Puravikud – Estonian

9. Eekhoorntjes brood – Dutch

10. King bolete – mushroom geek language

Boletus Edulis Time-Lapse

Where To Find The Boletus Edulis Mushroom

King boletes are mycorrhizal and are most commonly found under hemlock and oak especially where sphagnum mosses are present. They are also fairly common under most varieties of spruce.

Lawns and grass under conifers are another common habitat. Technically, true Boletus edulis will be found under conifers like hemlock and spruce but there are many unexplainable finds.

In Maine they will be found from the end of August through the middle November. Some field guides will say they are uncommon in the east which is not remotely true in my experience.

Boletus Edulis Identification

1. Cap

   White when very young, maturing to look like a crusty brown roll, hence the name penny bun. The edge of the cap is often white. Bulbous while young with the underside flattening when mature, brown to reddish-brown. Slug marks expose white flesh.

2. Pores

   Has very small white pores which can yellow a bit with age.

3. Stem

   Thick, bulbous and white ageing to slightly tan yellow. The stem has a fine net like covering just under the cap and sometimes extending all the way down the stem, solid when young, fresh or free from maggots.

4. Taste / Smell

   Excellent raw or fried in butter when fresh. Very mushroomy, one of the best species to dry where the mushroom flavor is enhanced.

5. Flesh: White slightly yellowing with age.

6. Habitat: Mixed woodland but found more with beech, oak or pine.

7. Spore Print: Green/brown. Subfusiform.

Boletus Edulis Look-Alikes

No poisonous mushrooms look similar, all the poisonous Boletus such as the Satans Boletus are either very red in the flesh or sponge, or stain blue immediately on cutting.

You could potentially confuse this mushroom with the Bitter Bolete, Tylopilus felleus which although not poisonous will ruin any meal you are unfortunate enough to add this mushroom too.

A little nibble of the mushroom when raw will soon identify it with the Penny Bun being delicious and the Bitter Bolete being as bitter as sin!

A better way to distinguish the two is that the Penny Bun has a lighter net like mesh on a slightly darker stem, the Bitter Bolete has a darker mesh on a lighter stem, pictured.

The Summer Bolete, Boletus reticulatus, looks very similar but has a slightly darker stem, not as solid flesh, lacks the white cap edge and grows in early Summer.

Boletus Edulis Cultivation

Boletus Edulis is parasitic mushroom it means that when an organism lives on another living creature without giving it any support, or rather getting it sick or killing it.

On the contrary, symbiosis happens to be a mutual or mychorrizal process when it consists of an exchange of nutritional favors.

As a result, an intimate link between mushroom and host plant gets established, so that you can cultivate this type of mushroom only if it is close to its plant.

For this reason, it is quite difficult – if not impossible – to cultivate a mychorrizal mushroom.

A very common example of symbiont is truffle, which is cultivated on mychorrizal plants.

Following the same procedure, the cultivation of boletus has also been pursued by mychorrizing host plants.

Can You Eat Boletus Edulis Raw?

Depends who you talk to. This is one of the few wild mushrooms that we have seen served raw and have eaten raw ourselves. The literature will often advise against this, and you certainly want to be moderate when eating any kind of mushroom for the first time, but on the other hand Russian tradition used raw porcini to promote intestinal health.

Slices of raw fresh porcini buttons are sweet and delicious but it is highly unlikely that you will ever find these unless you are picking them in the forest yourselves. Porcini that is passed the ‘button’ stage or that is more than a day or two old will be less sweet and more gamey, less firm and more spongy, and it is unlikely that you are the first one snacking on it.

Mature mushrooms are delicious when cooked and can be dried.

Recipe: Grilled Porcini Mushrooms with Mint and Garlic

Ingredients

1. 1 teaspoon minced flat-leaf parsley leaves

2. 1 teaspoon minced thyme leaves

3. 1 teaspoon minced rosemary leaves

4. 1 teaspoon minced mint leaves

5. 2 cloves garlic, minced

6. 1/3 cup extra-virgin olive oil, plus more for brushing

7. 1 pound porcini mushrooms (about 6 medium)

Instructions

1. Light a medium fire in a charcoal grill.

2. In a small bowl, stir together the herbs, garlic, and 1/3 cup olive oil.

3. Clean the mushrooms with a damp cloth. If desired, cut the mushrooms into 1/2-inch-thick slices and lightly brush them with oil. Grill until lightly browned, about 3 minutes per side. Transfer to a serving platter and brush with the herb-oil mixture. Serve at once.

Recipe: Tagliatelle with Boletus Edulis Mushrooms

Ingredients

1. 400 g tagliatelle (14oz) fresh or dried

2. 500 g of fresh or frozen porcini mushrooms (17oz) See recipe notes about using dried porcini

3. ½ glass white wine

4. 3-4 fresh nepitella small leafed wild mint sprigs or thyme

5. 2-3 tbsp extra virgin olive oil

6. 2 garlic cloves peeled

7. 2 tbsp unsalted butter

8. salt and pepper to taste

9. grated parmesan for serving

Instructions

1. Put water on to boil for the pasta. Add salt once it starts to boil.

2. Clean the mushrooms by cutting off the end of the stalk. It would be better not to rinse with water, given that the fungus absorbs it. You can use a small brush to remove any soil, or a damp cloth.

3. Cut the mushrooms into pieces

4. Fry the peeled garlic cloves in the olive oil, then remove them when golden and add the mushrooms.

5. Cook them for about 3-4 minutes.

6. Add wine and nepitella or thyme, increase the heat and cook until the alcohol has evaporated

7. Reduce the heat and add salt and pepper.

8. Continue to cook for about another 10-15 minutes. Remove from the heat once mushrooms are cooked through and add the butter.

9. Cook the pasta in salted boiling water, remove a glass of the pasta cooking water to be used later and then drain and add the pasta to the pan with the mushrooms and butter.

10. Toss everything together. The pasta absorbs liquid very quickly so if it looks too dry, add a little of the pasta cooking water at a time until you get the right creaminess.

11. Serve immediately with grated parmesan as required.

Using dried porcini

Because dried porcini have a very strong taste and are expensive, we suggest mixing them with some cremini or white champignon/button mushrooms. That way you also get nice pieces of mushroom in the sauce. 60g (2oz) dried porcini & 400g (14oz) other mushrooms.

Soak the dried porcini in bowl of warm water for about 30 minutes before draining and cooking (the water should cover the mushrooms). You can use a bit of the soaking liquid in the sauce.

Recipe: Pappardelle with Lemon, Garlic and Porcini Mushrooms

Ingredients

1. 455g pappardelle pasta (if you can’t get hold of pappardelle, linguine works well too)

2. Juice of half a lemon

3. 60g parmesan cheese, grated

4. 2 garlic cloves

5. 25g Merchant Gourmet Dried Porcini mushrooms

6. 1 small glass white wine

7. 300g fresh chestnut mushrooms, sliced

8. 75g butter

9. Handful parsley, chopped

Instructions

1. Place the Porcini Mushrooms in a small bowl, cover with boiling water and leave to rehydrate for 15 minutes.

2. Melt the butter in a frying pan, and fry the chestnut mushrooms on a moderate heat for 3 minutes.

3. Lift the rehydrated Porcini Mushrooms from the bowl and fry with the chestnut mushrooms for 2 minutes.

4. Peel, and finely slice the garlic and add to the pan with a few grinds of salt and pepper.

5. Stir the mushroom from time to time allowing them to go nicely golden.

6. Bring a large pan of salted water to the boil and cook the pasta according to pack instructions.

7. Place the wine and half of the mushroomy water into the frying pan, and allow to simmer on a gentle heat.

8. When the pasta is ready, drain and add to the mushrooms.

9. Throw in the parsley, parmesan and fresh lemon juice, and toss so that all the pasta is nicely covered. Serve.

Recipe: True Italian Porcini Mushroom Risotto

Ingredients

1. 1 ounce dried porcini mushrooms

2. 1 cup hot water

3. 1 (32 ounce) carton beef stock

4. ¼ cup olive oil, divided

5. 3 cloves garlic

6. 1 teaspoon dried rosemary

7. salt and ground black pepper to taste

8. 1 cup white wine, divided

9. ¼ cup butter, divided

10. 1 shallot, chopped

11. 1 ¾ cups Arborio rice

12. ⅓ cup grated Parmesan cheese

Instructions

1. Place porcini mushrooms in a bowl and cover with hot water. Let soak until soft, about 1 hour. Drain, reserving soaking liquid. Squeeze mushrooms to remove excess water and roughly chop.

2. Bring beef stock to a boil in a saucepan. Reduce heat to low and cover to keep warm.

3. Heat 3 tablespoons oil in a skillet over medium heat. Add garlic cloves; cook until fragrant, about 2 minutes. Add mushrooms; cook and stir until soft, 5 to 6 minutes. Season with rosemary, salt, and pepper. Discard garlic cloves; pour in 1/2 cup wine. Increase heat to medium-high and simmer until wine reduces, 3 to 5 minutes.

4. Heat remaining 1 tablespoon oil with 2 tablespoons butter in a saucepan over medium-low heat. Cook and stir shallot until soft, about 3 minutes. Cook and stir Arborio rice until toasted and fragrant, about 3 minutes. Pour in remaining 1/2 cup wine. Simmer until wine is absorbed, about 3 minutes.

5. Ladle 1/3 of the warm stock into the saucepan; cook and stir until absorbed. Ladle in remaining stock and reserved soaking liquid in small amounts and cook, stirring constantly, until risotto is tender and creamy, 15 to 18 minutes.

6. Remove risotto from the heat; stir in remaining 2 tablespoons butter and Parmesan cheese. Let stand for 3 to 5 minutes before serving.