How to forage for and preserve Porcini mushrooms, an easy to identify wild mushroom with delicious gourmet flavour
Porcini, latin name Boletus edulis, are prized among wild mushrooms for their flavor. They’re richer and more mushroomy than any conventional mushroom and also extremely easy to identify. Known also as the Cep or the Pennybun, it has a rich brown skin on its cap, sponge-like underside to the cap, and a sturdy white stem. It can’t really be confused with anything else other than what it is.
If you’re fortunate to live in an area where they grow, head out to find them between September to November. They taste delicious and it’s fun to look for them among the trees.
Avoid larger mushrooms if possible
The main challenges in foraging for this ‘King of Mushrooms’ is that locations where they grow are closely guarded secrets and that mature specimens are almost always found by pests first. I say pests to not creep anyone out. In fact the little white creatures you find when slicing your mushrooms is a type of maggot. If the mushroom isn’t too riddled with them you can still go ahead and use it – just try to remove any creepy crawlies first.
You can of course bypass these larger mushrooms and look for the youngsters. Because they’ve not fully opened their gills up to the air, pests have a harder time burrowing in.
Pick porcini when they’re young
Porcini can be harvested very young and at just four to six inches in height. When they’re this fresh out of the ground the flesh is almost completely white and the mushroom can be sliced and pan fried. As the mushroom grows older it also grows mush bigger – we’re talking a foot wide and tall. At this stage the pores on the underside of the cap start elongating and turning green-yellow. It’s still very much edible but is better suited for risottos and pasta dishes since this spore part tends to become a bit slimy.
You can find Porcini growing under conifers like spruce, pine, and hemlock, but also under oak. A sign they might be about is spotting mushrooms in the Amanita family such as the iconic red and white Fly Agaric. This is the mushroom you’ll see pictured in children’s books and is often referred to as the most iconic of Toadstools. See more about finding Porcini in the wild in this post.
Pick them from late summer to autumn and use both the cap and stem within a day or two or they’ll go off. If you pick a lot of them, as I did last weekend, you’ll want to preserve them quickly and the way I’ve done it the past two seasons is to dry them in a food dehydrator.
How to dry porcini mushrooms
Drying Porcini is easy. First clean the stem and cap with a damp cloth to remove dirt, debris, pine needles, etc., but don’t immerse the mushroom in water or it may become slimy. The top of the cap will have a brown skin that most people prefer to remove. You can do this by peeling it back with your fingers or if that’s difficult, slice the mushroom up and pull the skin off afterwards.
The slices should be relatively thin and no more than a quarter inch thick. Lay them on the racks inside your food dehydrator and set the heat at 40°C / 110°F for between two to six hours. The length of time will depend on how many racks you have in the unit and how thick you’ve sliced the mushrooms.
Dried mushrooms are versatile
Once dried, the mushrooms can be a little flexible but light and not squishy to the touch. Allow them to cool to room temperature then store them in a sealed container like tupperware or a mason jar. Kept out of the light they’ll last at least a year.
You use dried porcini in cooking by reconstituting them first. Cover a handful with boiling water and both the mushrooms and the resulting broth is delicious in risottos, pasta and other savoury dishes.
One way to use Porcini pieces that are small or odd, or from the stem is to first dry the mushroom and then pulse it into a powder. Use the powder to make broth, sauces, or flavour homemade dishes like pasta. Last year I used Porcini powder to flavour handmade Gnocchi and I have plans to do the same this week for friends. Here’s the recipe if you’d like to try it out too.