Cooking Porcini Mushrooms – Tips and Tricks

One of the most distressing experiences in mycophagy (the practice of eating exotic mushrooms while being a word nerd who makes up silly names for routine matters like lunch) is trying a mushroom that everyone raves about and being disappointed or outright disgusted by it. My first experience with porcini mushrooms was one such sad occasion, but in my defense I had no clue how to properly prepare them and did a piss-poor job of researching the matter before I dove into the kitchen. Here are some hints and pointers for using porcini mushrooms in your next great mushroom feast!

Porcini mushroom
A mature wild porcini mushroom, Boletus rex-veris. Photo by Anna McHugh

Porcini Mushroom Overview

Porcini is the Italian name for Boletus edulis, a wild mushroom that is highly esteemed throughout Europe and North America. These mushrooms have a multitude of common names, and strictly speaking there are numerous species of Boletus mushrooms that are sold under the name porcini. Look out for a post later this week that addresses some of the different species that count as “porcini.”

Dried porcini mushrooms are readily available at most grocery stores, and they are among the most commercialized wild mushrooms in the world. Porcini possess a nutty, earthy character that is pleasantly counterbalanced by a bit of sweetness and bitterness that, on the whole, creates a complex and enchanting flavor profile.

Call them what you like, the porcini mushroom is one of the finest wild culinary mushrooms on the market, and is by far the most coveted Boletus mushroom you can find in the wild. However, they require special handling and preparation; due to their high moisture content, they need to be treated with dignity rather than impunity, otherwise you run the risk of eating porcini that are soggy, slimy, or even leathery.

Boletus mushrooms are a special (and large) group of mushrooms that have a classic cap-and-stem fruiting body. The thing that sets them apart from, say, a portobello is their fertile tissue. Instead of blade-like gills on the bottom of the cap, Boletus mushrooms have a spongy layer of tissue that’s made up of a multitude of little tubes. The sponge can be white, red, yellow, brown, ochre-greenish…the list of possible sponge colors is quite long. In the case of porcini, they start out white and turn yellowish as the mushroom matures. In many cases, the woes and pitfalls of cooking porcini is linked to that sponge, because unlike the rest of the mushroom’s flesh, the sponge is, well, spongy. It can get filled with grit (gross), or turn slimy when cooked improperly.

Porcini mushroom
Mature porcini mushroom, Boletus rex-veris. Note the yellowish spongy layer under the cap. This specimen is an ideal candidate for the dehydrator on account of its advanced age. Photo by Anna McHugh

Tips on Cooking Porcini Mushrooms

Whether dried or fresh, porcini require some special attention. Unlike lobster mushrooms, king oyster mushrooms, hedgehog mushrooms, and other resilient fungi that you can cook without fear of mushiness, porcini are temperamental because they can easily fall apart or turn towards the squish if you add too much stock, oil, or sauce while cooking them; like chanterelle mushrooms, porcini soak up the surrounding fluid like a fungal-sponge. Here are just a few ways to make them delicious, sorted according to whether you’re working with dried or fresh mushrooms.

Fresh Porcini

Some people truly love dried porcini and put them on and in things at an alarming rate. The number of recipes I have seen that include whole reconstituted porcini mushrooms is astonishing to me. Although they aren’t as pungent and flavorful, I really love fresh porcini, especially when they are young and very firm. They have a delightful crunch and their flavor is, on the whole, more delicate and nuanced than the one-two earth-nut punch of a dried porcini.

Ideally, porcini buttons are best for cooking these mushrooms fresh; they are firm throughout and the spongy layer under the cap is not soggy or soft. If you are cooking with fresh mature porcini, I strongly encourage you to remove the sponge altogether and use it to make stock rather than attempting to prepare the whole mushroom. The spongy layer on porcini (and other Boletus mushrooms) usually peels off the underside of the cap with ease. Here are a few other tips on cooking fresh porcini mushrooms.

Porcini mushroom buttons
Porcini mushroom buttons of the species Boletus rex-veris (Spring King bolete). When cooking fresh porcini, young mushrooms are the best because their sponge layer is almost as firm as the mushroom’s flesh. Photo by Anna McHugh.
  1. Grill them. Slice your porcini semi-thin (about 1/2-inch) and brush them with light oil and add a bit of salt and pepper. If you are working with reasonably small caps, you can simply use the cap in its entirety, but I do not strongly recommend doing so if the caps are thicker than one inch. If desired, place them on foil or a pizza sheet and stick them on a medium-hot grill (the same temperature you would use for chicken). Let them grill for about 5 minutes, then flip them. If they start to char, move them to a cooler section of the grill; once porcini start to char on the edges, they develop a bitterness that renders them less-perfect (still perfectly edible, but not as good as golden-brown grilled porcini). If desired, slice them up and add them to risotto or salad. My favorite use of grilled porcini is to add them to gnocchi with a cream-based sauce. I grill the porcini and make the sauce, then add the porcini to simmer in the sauce for 4-5 minutes; any longer than that, and you run the risk of the porcini becoming too soft. The grilling does a nice job of keeping the porcini intact once they’re introduced to the sauce, rather than soaking up the cream and becoming mushy.
  2. Serve them raw. Porcini are one of the few wild mushrooms that can be eaten raw without running the risk of gastrointestinal upset. Like all foods, some people are allergic and might experience a sour belly from raw porcini – however, this is uncommon and I have yet to encounter anyone who has had this problem. If you plan to eat porcini raw, slice them very thin and sprinkle with a little extra virgin olive oil, a touch of vinegar (either balsamic or red wine, depending on your preference), and a sprinkle of fresh herbs like thyme or oregano if desired.
  3. Saute them. If you don’t have a grill or don’t want to bother with getting a fire going, you can saute fresh porcini mushrooms. Start with pan that has only the slightest bit of oil in it; once the mushrooms start to saute they will drop a good bit of moisture into the pan, and if you have an excess of oil, the porcini will soak it up and become soggy. Saute the mushrooms on medium-high heat for 5-7 minutes on each side and do not stir them much; keep them moving just enough so they don’t stick to the pan. Once sauteed, they can be used in quiches, omelettes, in calzones, or whatever else you might decide to cook with mushrooms as an ingredient.
  4. Roast them. Another good option is to roast your porcini. Ideally, use whole caps or thick slices of larger porcini mushrooms. Brush both sides liberally with oil, sprinkle with salt, pepper, and (if desired) parsley and place in an oven preheated to around 400 degrees. Roast for about 10 minutes, flipping the mushrooms around the 5-minute mark. If you have one, a large steel in your oven does wonders for roasting porcini; the steel becomes very hot while preheating and transfers the heat directly to the mushrooms, giving them a nice crisp on the edges that is less likely to occur without a steel. Alternately, you can heat a cast-iron skillet in the oven for 10 minutes at 400 degrees and then carefully place the oiled and seasoned porcini in the pan and proceed to roast them for 4-5 minutes on each side.

Dried Porcini

If you hunt wild mushrooms and end up with a huge haul of Boletus, I strongly encourage you to dehydrate them. Most other wild mushrooms on my menu over the years are much better when sauteed and frozen, but drying porcini enhances their flavor and aroma. Alas, once dried, they have a tendency to reconstitute a little inconsistently; the sponge comes back slimy, and the cap comes back leathery. To mitigate this, I avail myself of the following techniques:

Porcini mushroom slices
Slices of porcini mushroom caps on a dehydrator. Note the yellow sponge. Photo by Anna McHugh.
  1. Powder the porcini. My favorite use of dried porcini is to powder them and then add them to dishes I will be roasting or grilling. Using a food processor or mortar and pestle, grind the mushrooms as fine as you can get them. In order to avoid clumping, I usually add a little bit of salt to the porcini powder and store in an airtight container. When I want a dash of porcini flavor in a dish I’m making, I put a teaspoon or two (or sometimes three) on fish, vegetables, or whatever else. Porcini powder is also awesome on garlic bread; it adds a nice savory flavor that complements garlic quite well. As luck would have it, the flavor of dried porcini is strong enough that a little bit of powder goes a long way!
  2. Remove the sponge and just use the flesh. Even though they become withered little beings when you stick them in the dehydrator, it is usually quite easy to separate the sponge from the flesh of a dried porcini. Simply crumble off the sponge and either discard them or use them as you see fit. If you plan to use them, I strongly suggest mashing or grinding them up, because they have a nice flavor but their spongy consistency is a little off-putting. Once you are simply dealing with the mushroom flesh, saute them lightly in some of the water you used to rehydrate them (this water will take on a lot of the porcini’s flavor and you can use the water to preserve as much of this delightful taste as possible), along with some light oil, butter, and/or white wine. Be careful not to simmer them for too long; 5-7 minutes should be sufficient. Once the liquid has simmered off, you can then add them to casseroles, use them to top a pizza, or hit them hard with more oil/butter and saute them to make crunchy, crispy mushroom-bits for your baked potato, salad, or whatever else you want them on.
  3. Puree the mushrooms. One of the finest mushroom dishes in the world is cream of porcini and chanterelle soup. Start with dried porcini, rehydrate them, and reserve the soaking water. Puree the mushrooms and add both pureed mushrooms and some (or all) of the soaking water to a cream of mushroom soup recipe and you’re in business!

Buying Good Porcini

Finding true porcini mushrooms is not possible in some parts of the United States. Although Boletus mushrooms that could be considered porcini do grow in the Rocky Mountains and western United States, the east coast is sadly bereft of Boletus edulis, the classic “porcini.” However, not to fear! There are plenty of options if you want to purchase and sample porcini. High-end grocery stores all carry it, and many middle of the road stores do as well.

One thing to note when buying commercial porcini is that you’re likely to get less-than-stellar mushrooms. In the field, mushroom hunters who collect choice porcini can sell them for high prices to gourmet restaurants and suppliers, and the “leavings” are what ends up being dried and packaged for sale. The consequences of this: buggy mushrooms, along with an inordinate amount of spongy fertile material, sometimes ends up in packages of dried porcini mushrooms.

Since porcini are notoriously attractive to flies as a place to deposit larvae, much of the dried porcini in stores is riddled with worm-holes. This is not necessarily bad, but I do take the time to inspect dried porcini and select a package that has minimal insect damage. Also, I try to find a package that has the largest amount of mushroom flesh, and the least amount of sponge. You can visually tell the difference between sponge and flesh, as luck would have it, and since the flesh is more flavorful and resilient during cooking, I try to get as much of that as I can. In an ideal world, picking dried porcini from a large jar that you can weigh out yourself is the best; just grab the mushroom-bits that look most appealing to you, and leave the worm-eaten specimens to less fortunate shoppers!

Hunting for Porcini

Porcini mushrooms native to the Rocky Mountains grow in the late summer months, when torrential summer storms bring out a profusion of fungi of all types. Further west, in the Sierra Nevada, the admirable porcini known as Boletus rex-veris (The Spring King bolete) comes up when the winter snows melt and leave the ground soaked in the late spring. When I lived out west, the Spring King was my bag; I would wait until just around Memorial Day and head up to 5,000-8,000 feet elevation, and cruise around about 300′ below the snow line. Invariably, I would find abundant Spring King boletes.

Porcini mushroom haul
A large collection of wild-foraged porcini. There was no shortage of cream of mushroom soup after this particular outing! Photo by Anna McHugh.

One time they were so numerous that my friends and I wore out our feet hiking. Instead of giving up, we changed tactics: we drove at a leisurely pace along forest service roads for a couple hours, our eyes scanning the landscape. We were lucky, too, because ultimately we found a few patches that were so large that we filled several shopping bags without breaking a sweat, and we remarked that if we had been on foot, there would be no way for us to get all our loot back to camp.

Final Thoughts on Porcini

Whatever you do, don’t give up on porcini! Even if you have an experience that isn’t terrific, it’s more likely than not that you’ll find your stride with them, and if you simply don’t have magic hands in the kitchen (as I do not), there are plenty of ways to get around your lack of culinary genius (powdering them being my personal favorite). My first experience with porcini left me shaking my head and asking myself what all the fuss was about with these mushrooms. About a month later, a good friend gifted me a basketful of fresh Boletus edulis and commanded me to do my homework and try again. I am extremely glad he did, and now I would never allow my kitchen to be a porcini-less wasteland.


5 thoughts on “Cooking Porcini Mushrooms – Tips and Tricks”

  1. Man, I love boletus! I have discovered that when I dry and grind them to powder, I can add 1 tbs. of onion powder, 1 tbs. Garlic powder, 1 tbs. salt (optional) to each cup of mushroom powder. It’s addictive! I have my whole family hooked. Gotta try the crispy chips for salad though…

    1. Thanks for the porcini powder suggestion! I usually mix it with salt and garlic powder, then throw in a dash of herbs of some type. The onion powder, however, sounds like a real winner!

    1. Porcini do not revive terribly well when frozen; they tend to lose their shape and become limp and floppy. If you’re planning to blend them (for instance for a cream of mushroom soup), this doesn’t cause a problem. For best results with freezing porcini (and any other mushroom that has a high water content), saute and then freeze in layers. Drying is strongly preferred, the dehydration process intensifies their flavor and they reconstitute nicely.

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