Cooking guide

How Long to Cook Penny Bun Mushrooms

Sliced28 to 35 minutes
Halved or whole35 to 40 minutes

The penny bun (Boletus edulis) — also known as porcini, cep, or king bolete — is widely considered the finest edible mushroom. Its dense, white flesh and incomparable nutty, earthy flavor make it the ultimate ingredient for soups, sauces, and risotto.

  • Brush clean well
  • Gentle simmer
  • King of mushrooms
Penny bun mushroom (Boletus edulis / porcini)
Photo: Tomasz Przechlewski – CC BY 2.0 | cropped to square

Quick answer

Quick Answer

Sliced28 to 35 min

Gentle simmer

Halved35 to 40 min

Dense flesh needs time

Whole, small35 to 40 min

Check with knife tip

For porcini broth35 to 45 min

Exceptional flavor

Water change neededNo (if certain)

Yes if uncertain

Soaking requiredNo

Brush clean, rinse

Calculator

Penny Bun Cooking Time Calculator

Use this as a quick estimate. Read the method below for preparation and doneness tips.

Estimated cooking time 28 to 35 minutes

Cooking temperature: liquid at 82 to 90°C / 180 to 194°F. Start timing once the water reaches a gentle simmer.

These estimates assume fresh penny bun mushrooms, cleaned and trimmed.

Preparation

How to Prepare Penny Bun Mushrooms Before Cooking

Clean penny bun mushrooms thoroughly with a stiff brush, working from the cap center outward and down the stem. The smooth brown cap and thick bulbous stem trap soil. Rinse briefly under cold water and pat dry. Do not soak.

Inspect each mushroom carefully: cut through the stem and check for insects. Small worm holes in the stem base are common and can be trimmed away, but extensive tunneling through the entire flesh means the mushroom is past its prime. Trim the stem base generously.

The yellow-to-white tube layer (pores) under the cap is edible and very flavorful in young specimens. On very large or old mushrooms it becomes greenish and spongy — scrape it away in those cases. Slice into thick pieces or halve for even cooking.

Method

How to Cook Penny Bun Mushrooms Step by Step

  1. Brush caps and stems thoroughly. Rinse briefly and pat dry.
  2. Inspect the flesh for insect damage. Trim the stem base generously.
  3. Optionally remove the tube layer on large or old specimens.
  4. Slice into thick pieces or halve.
  5. Place in a pot and cover completely with cold water.
  6. Bring to a gentle simmer over medium heat.
  7. Skim foam carefully during the first 5 to 10 minutes.
  8. Cook sliced pieces 28 to 35 minutes, halved pieces 35 to 40 minutes.
  9. Salt the water towards the end of cooking.
  10. Season with pepper, bay leaf, allspice, and marjoram to taste.
  11. Drain and save the deeply flavorful cooking liquid.

Cooking chart

Penny Bun Cooking Time Chart

Form Method Time Notes
Sliced thick Gentle simmer 28 to 35 minutes For soups, pasta sauces, and risotto.
Halved Gentle simmer 35 to 40 minutes For stews and hearty dishes.
Whole, small to medium Gentle simmer 35 to 40 minutes For marinating or elegant presentation.
Very large or dense Gentle simmer 40 to 50 minutes Thick, dense flesh requires more time.
Porcini broth Simmer 35 to 45 minutes Produces an extraordinary, deeply savory broth.

Doneness

How to Know When Penny Bun Mushrooms Are Done

Penny bun mushrooms are done when the flesh is completely tender throughout — a knife tip should pass through the thickest part with no resistance. The white flesh turns to a pale brown. The cooking liquid will be a deep amber-brown with an intensely earthy, nutty aroma. Do not rush — undercooking leaves the dense flesh with a rubbery core.

Safety note: penny bun (Boletus edulis) is a well-known, safe edible mushroom when positively identified. Avoid any boletus with red pore surfaces or flesh that turns blue immediately when cut — these may be toxic. If uncertain of the species, change the cooking water once or twice, or do not eat the mushrooms.

The king of mushrooms

Why Penny Bun Is Called the King of Mushrooms

The penny bun or porcini is revered across European and Italian cuisine for its dense, firm flesh and extraordinarily rich, nutty, earthy flavor. Unlike most mushrooms, its flavor intensifies dramatically when dried — dried porcini is one of the most powerful flavor ingredients in cooking. Even the cooking water from fresh penny bun is exceptional and is used extensively in Italian, French, and Eastern European cooking.

Seasoning

Best Seasonings for Penny Bun Mushrooms

Penny bun mushrooms have a strong, self-sufficient flavor that needs minimal intervention. Bay leaf, black pepper, allspice, marjoram, thyme, garlic, and parsley complement without overpowering. In Italian-style dishes, olive oil, garlic, and fresh thyme are the classic partners. Butter, cream, and Parmesan bring out their nutty, earthy depth.

Avoid this

Common Mistakes

  • Not inspecting for insects — penny bun is very prone to insect infestation.
  • Undercooking — the dense flesh needs the full cooking time.
  • Boiling hard instead of simmering — hard boiling makes the flesh mushy.
  • Discarding the cooking liquid — porcini broth is exceptional.
  • Leaving a very dark, slimy tube layer on older specimens — it can make the broth bitter.

Serving

What to Serve With Cooked Penny Bun Mushrooms

Penny bun mushrooms are exceptional in pasta, risotto, barley, buckwheat, polenta, scrambled eggs, roast meats, and game dishes. Their intense flavor enhances any dish where a deep, woodsy note is desired. They are a natural partner for cream sauces, butter, and aged cheeses.

Recipe ideas

Penny Bun Recipes You May Like

  • Porcini risottoUse cooked penny bun and their exceptional broth as the entire base of a classic Italian risotto.
  • Tagliatelle ai funghi porciniToss sliced cooked penny bun with pasta, garlic, parsley, butter, and the cooking liquid.
  • Mushroom soupSimmer sliced penny bun with potato, onion, and cream for a deeply earthy soup.
  • Buckwheat with porciniCombine cooked penny bun with buckwheat, fried onion, and butter.
  • Game meat sauceReduce cooked penny bun with their broth, red wine, and cream for a sauce for venison or boar.
  • Marinated porciniCook small whole mushrooms, cool in the broth, and marinate with olive oil, garlic, and herbs.

Leftovers

How to Store and Reheat Cooked Penny Bun Mushrooms

Cool cooked penny bun quickly and refrigerate in an airtight container within 2 hours. Use within 2 to 3 days. Reheat gently in their broth, butter, or sauce. The cooking liquid keeps refrigerated for 3 days or frozen for up to 3 months. Cooked penny bun can be frozen — the firm flesh tolerates freezing better than many mushrooms.

Tools

Useful Tools for Cooking Penny Bun Mushrooms

  • Stiff brushEssential for removing soil from the thick cap and bulbous stem.
  • Sharp knifeFor slicing the very dense flesh cleanly.
  • Large saucepanPenny bun are large; use a pot with room to cover them fully.
  • SkimmerFor removing foam during the first minutes of simmering.
  • Fine strainerFor straining the exceptional cooking broth.

Questions

FAQ

How long should penny bun mushrooms be cooked?

Sliced penny bun mushrooms cook in 28 to 35 minutes at a gentle simmer. Halved or whole pieces take 35 to 40 minutes. The dense flesh needs adequate time — do not rush.

What is the difference between penny bun and boletus?

Penny bun (Boletus edulis) is a specific species within the broader boletus group. Also known as porcini or cep, it is considered the finest edible bolete with a richer, more intense flavor and firmer flesh than most other boletus species.

Can penny bun mushrooms be eaten raw?

Young, very firm penny bun can be thinly sliced and eaten raw with olive oil, lemon, and Parmesan in Italian-style porcini carpaccio. For cooking, however, they need the full cooking time to become tender and develop their full flavor.

How do I spot insect damage in penny bun?

Cut the stem lengthwise and look for tunnels. Small holes at the stem base are common. Extensive tunneling throughout the cap and upper stem means the mushroom is over-ripe. Trim away any affected parts and use the rest promptly.

Do penny bun mushrooms need a water change during cooking?

For properly identified penny bun, no water change is needed and the broth is exceptional. If there is any doubt about the species, change the water once or twice as a precaution, or do not eat them.

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