Boletus edulis

Description

Boletus edulis is a mushroom that has pores instead of gills and is the type species of the Boletus genus. It is large and can be yellow-brown to reddish-brown in color. It grows under various trees, such as conifers, birches, oaks, and beeches, and can be found all over the world. This mushroom is highly valued for its taste and texture, but can be difficult to find since it often grows hidden beneath the soil surface. Experienced hunters look for small humps in the litter as indicators of the mushroom's presence.

It is also a popular ingredient in many cuisines and is used in various dishes such as soups, sauces, and risottos. Moreover, the nutritional value of Boletus edulis is noteworthy, as it is a good source of protein, fiber, and various minerals and vitamins such as copper, potassium, and vitamin B12. However, it is important to note that while Boletus edulis is generally considered safe to eat, there are some poisonous look-alike species, so it is important to be able to properly identify the mushroom before consuming it.

The largest Boletus edulis mushroom ever recorded was found in Poland, weighing a whopping 6.6 lbs (3 kg). This massive porcini mushroom was in excellent condition, with firm flesh and a delightful fragrance, and was free of any signs of infestation.

Common names: King Bolete, Penny Bun, France (Cèpe de Bordeaux), Spain (Rodellon), German (Steinpilz), Czech Republic (Hřib smrkový), Estonia (Puravikud) Dutch (Eekhoorntjes Brood), Netherlands (Gewoon eekhoorntjesbrood).

Mushroom Identification

1. Cap

   The cap is 1.97 to 7.87 inches (5 to 20 cm) in diameter, fleshy, initially hemispherical, later convex-spread, pillow-like, spread, flat-spread. The surface is initially pubescent, later smooth, slightly wrinkled, matte, slippery in wet weather, shiny, yellowish-brown, chestnut-brown, dark brown, grayish-brown, and does not change color in places of contact.

2. Pores

   The hymenophore is tubular. Pores are small, rounded, initially whitish, grayish, with age yellow-green, yellow-olive.

3. Stem

   The stem is 1.97 to 7.87 inches (5 to 20 cm) high, 0.79 to 2.76 inches (2 to 7 cm) in diameter, initially bulbous, later club-shaped, expanded to the base, longitudinally wrinkled, dense, fleshy, solid, white, grayish, grayish-brownish, ocher, light brown.

4. Flesh

   White slightly yellowing with age.

5. Spores

   Spores 12-19 * 4-6 μm, spindle-shaped, rarely elongated.

6. Spore Print

   Olive-brown.

7. Odor and Taste

   The taste and smell are very mushroomy, one of the best species to dry where the mushroom flavor is enhanced.

8. Habitat

   King boletes are a type of fungus that grow in a mycorrhizal association with trees, particularly hemlock, oak, spruce, and other conifers. They can also be found in lawns and grassy areas under conifers. They are most abundant from June to October in forests of all types, especially in young spruces or at their edges, and can grow at various elevations. They can also grow outside the forest wherever the roots of trees reach, forming a symbiotic relationship with the trees.

Look-Alikes

1. 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.

2. Tylopilus felleus

   Has a strongly bitter flesh, the tubes of which gradually turn pink.

3. Boletus pinophilus

   Has a reddish tint on the cap skin.

4. Boletus aereus

   Usually darker, with olive or bronze hues. It is a thermophilic species forming a mycorrhiza with oaks on calcareous soils.

Time-Lapse

Cultivation Tips

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?

Boletus edulis is one of the few wild mushrooms that can be served raw. The literature will often advise against this, and you certainly want to be moderate when eating any kind of mushroom for the first time.

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 spongy.

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.

History

In 1782 French botanist Pierre Bulliard described this species. Early alternate names include Boletus solidus by English naturalist James Sowerby in 1809, and Gray's Leccinum edule. Gray's transfer of the species to Leccinum was later determined to be inconsistent with the rules of botanical nomenclature, and he was unfamiliar with the earlier works of Fries when he published his arrangement of bolete species.

In Rolf Singer's classification of the Agaricales mushrooms, it is also the type species of section Boletus, a grouping of about 30 related boletes united by several characteristics: a mild-tasting, white flesh that does not change color when exposed to air; a smooth to distinctly raised, netted pattern over at least the uppermost portion of the stem; a yellow-brown or olive-brown spore print; white tubes that later become yellowish then greenish, which initially appear to be stuffed with cotton; and cystidia that are not strongly colored.

A molecular analysis published in 1997 established that the bolete mushrooms are all derived from a common ancestor, and established the Boletales as an order separate from the Agaricales.

The generic name is derived from the Latin term bōlētus "mushroom", which was borrowed in turn from the Ancient Greek βωλίτης, "terrestrial fungus". Ultimately, this last word derives from bōlos/βῶλος "lump", "clod", and, metaphorically, "mushroom". The βωλίτης of Galen, like the boletus of Latin writers like Martial, Seneca and Petronius, is often identified as the much prized Amanita caesarea.

The specific epithet edulis in Latin means "eatable" or "edible".

Synonyms

• Tubiporus edulis (Bull.) P. Karst

• Boletus betulicola (Vassilkov) Pilát & Dermek

• Boletus citrinus A. Venturi

• Boletus clavipes (Peck) Pilát & Dermek

• Boletus edulis f. albus (Pers.) J.A. Muñoz

• Boletus edulis f. arcticus Vassilkov

• Boletus edulis f. betulicola (Vassilkov) Vassilkov

• Boletus edulis f. citrinus (Pelt. ex E.-J. Gilbert) Vassilkov

• Boletus edulis f. citrinus J.A. Muñoz

• Boletus edulis f. edulis Bull.

• Boletus edulis f. laevipes (Massee) Vassilkov

• Boletus edulis f. olivaceobrunneus (Zeller & F.D. Bailey) Vassilkov

• Boletus edulis f. praecox Vassilkov

• Boletus edulis f. pseudopurpureus (Murr) Vassilkov

• Boletus edulis f. quercicola Vassilkov

• Boletus edulis f. roseipes Vassilkov

• Boletus edulis f. subaereus Vassilkov

• Boletus edulis f. tardus Vassilkov

• Boletus edulis subsp. betulicola (Vassilkov) Hlaváček [as 'betulicolus']

• Boletus edulis subsp. clavipes (Peck) Singer

• Boletus edulis subsp. edulis Bull.

• Boletus edulis subsp. euedulis (Maire) Singer

• Boletus edulis subsp. euedulis Maire

• Boletus edulis subsp. slovenicus (Smotl.) Hlaváček

• Boletus edulis subsp. trisporus Watling

• Boletus edulis var. abietis Schiemek

• Boletus edulis var. arcticus (Vassilkov) Hlaváček

• Boletus edulis var. arenarius H. Engel

• Boletus edulis var. betulicola Vassilkov

• Boletus edulis var. citrinus Pelt. ex E.-J. Gilbert

• Boletus edulis var. clavipes Peck

• Boletus edulis var. communis Alb. & Schwein.

• Boletus edulis var. edulis Bull.

• Boletus edulis var. elephantinus (With.) Pers.

• Boletus edulis var. elephantinus Massee

• Boletus edulis var. laevipes Massee

• Boletus edulis var. ochraceus A.H. Sm. & Thiers

• Boletus edulis var. piceicola Vassilkov

• Boletus edulis var. pseudopurpureus Murr

• Boletus edulis var. quercicola Vassilkov

• Boletus edulis var. quercus Schiemek

• Boletus edulis var. tuberosus Pers.

• Boletus elephantinus With.

• Boletus esculentus ß albus Pers.

• Boletus olivaceobrunneus Zeller & F.D. Bailey

• Boletus persoonii Bon

• Boletus quercicola (Vassilkov) Singer

• Boletus reticulatus var. albus (Pers.) Hlaváček

• Boletus reticulatus var. citrinus Hlaváček

• Boletus slovenicus Smotl.

• Boletus solidus Sowerby

• Boletus solidus Sowerby (1809)

• Boletus venturii Bon

• Ceriomyces crassus Battarra (1775)

• Dictyopus edulis (Bull.) Forq., 1886

• Dictyopus edulis var. edulis (Bull.) Quél.

• Leccinum edule (Bull.) Gray, 1821

• Leccinum elephantinum (With.) Gray

• Suillus citrinus (A. Venturi) Kuntze

• Tubiporus edulis (Bull.) P. Karst.

• Tubiporus edulis subsp. edulis (Bull.) P. Karst.

• Tubiporus edulis subsp. euedulis Maire

• Tylopilus porphyrosporus var. olivaceobrunneus (Zeller & F.D. Bailey) Wolfe

Photo sources:

Photo 1 - Author: Midnight Runner (CC BY-SA 4.0)

Photo 2 - Author: Björn S.. (CC BY-SA 2.0)

Photo 3 - Author: Holger Krisp (CC BY 3.0)

Photo 4 - Author: Midnight Runner (CC BY-SA 4.0)

Photo 5 - Author: Bernard Spragg (Public Domain)