"Every year come September, the price of mushrooms drops and I stock up on porcini," the famed Italian food writer Pellegrino Artusi wrote a century ago. He was talking about drying the fresh mushrooms to use in stews and sauces during the winter months, but we can be quite certain that fresh porcini figured prominently on his table as well: Boletus edulis is one of God's great gifts to humanity, a rich, heady, meaty mushroom that is amazingly versatile, delicate enough to give grace to an elegant stew or sauce, and yet vigorous enough to stand up to something as flavorful as a thick grilled steak accompanied by a good Barolo, for example, a good vintage of Ceretto's Bricco Rocche.
Porcini even look the way a mushroom should: A thick, firm white stalk and a broad, dark-brown cap -- if you're out walking in a European forest and come across a clump under a chestnut tree, where they're often found, you may well think you've stumbled into a fairy tale and look about for gnomes. Of course most of us don't have the time, nor the expertise required, to go mushroom hunting. So we buy our fresh porcini at the market (fresh porcini can be found in North America also, while Barbara Kafka points out that the French call them cèpes, the Germans Steinpilz or Herrenpilz, and the Russians Belyi Grib, and that they may appear under any of these names). They should be firm, with unblemished white stalks and brown caps, not nicked or broken. If the undersides of the caps have a yellowish-brown tinge to them, the mushrooms are heading into overripeness, and if they have black spots on them or the undercaps are deep green, they're already overripe.
The other thing you should look for is signs of worms (small holes).
As soon as you get your porcini home, scrape any dirt you may find off the stalks and wipe the mushrooms clean with a damp cloth -- only wash them if you absolutely must, and then never in hot water. They are now ready to use. If you plan on doing so immediately, perfect.
If, on the other hand, you must wait several hours, either remove the stalks or stand the mushrooms on their caps -- the stalks frequently contain tiny worms, which eat their way upwards and outwards. Though they're harmless, they're annoying.
A final thing about purchasing fresh porcini: Tuscan cooks season them with nepitella, a sort of small-leaved mint with hints of oregano. In other parts of Italy, parsley is used instead; I personally prefer the nepitella because it pairs so well with the mushrooms' strong flavor. Feel free to use either, or give thyme a try.
You can also buy dried porcini -- they obviously cannot be grilled, but do play an important role in the kitchen: they're blessed with a terrific savory aroma that adds a lot to stews and sauces, and can be used to make an excellent risotto.
In purchasing dried porcini, look them over carefully. If they're crumbly, they're likely old and probably won't have much flavor. If they're sold from a jar, breathe deeply when it's opened; you should smell a heady mushroom aroma (which is often strong enough to come through the packaging of a packet).
If there's no aroma, the mushrooms aren't going to taste of much. Finally, look the mushrooms over for pinholes, and if you see any, look in the bottom of the package for worms. They know a good thing when they smell it too.
To prepare dried porcini, steep them in just enough warm water to cover for 20 minutes or until they've softened and expanded. Drain them, reserving the liquid, and mince them. They're now ready for use in the recipe; if the recipe calls for liquid as well, filter the water they steeped in (it may contain sand) and add it too -- you'll get lots more mushroomy aroma.
Porcini Mushroom Recipes
- How to Cook Fresh Porcini Mushrooms
Suggestions for preparing fresh porcini mushrooms.
- Porcini Mushroom Risotto
A warming fall dish made with dried porcini mushrooms.
[Edited by Danette St. Onge]