If you want to pick mountain porcini, you best keep your ear to the wall. No one casually gives up their patches of porcini. It's hard enough to predict where and when the buggers will fruit as it is.
Here in the Cascades we get two, possibly three distinct fruitings of porcini: the spring variety, which is now officially known as Boletus rex-veris; and the summer/fall varieties, which might be distinct from each other but get lumped in together as a single species with the famous porcini of Italy, Boletus edulis. All varieties are deserving of their nickname "king bolete." With their firm flesh and nutty flavor, they might be my favorite wild mushrooms of all.
A couple weeks ago while picking huckleberries I got a tip from some hikers that a lot of mushrooms were fruiting to the south. The next day I hopped in the car and made an educated guess about where to go. Mountain porcini like high elevations, and they're picky about tree composition. True firs and spruce are the ticket. After a three-mile hike I started to see them—first some blown-out flags in the sunny areas and then fetching number one buttons emerging out of the duff in more shaded spots.
When picking porcini, always make sure to field dress them right away. I trim the end to check for worm holes, then cut the mushroom in half. Often a pristine looking bolete will show signs of bugs once you slice it open, but the infestations will just as often be local to a small area of the cap or stem that can be trimmed away. Whatever you do, don't simply put a porcino in your basket to trim later at home. I've learned the hard way that a basketful of beautiful buttons can be a worm-ridden mess by the time you get home if you don't deal with the bugs immediately.
By the end of the day I had nearly 10 pounds of mostly perfect porcini buttons (having thrown away twice that amount as too far gone). What a dilemma! I had more porcini than I could use. Some I cooked, some I gave away, and the rest got pickled.
Pia's Pickled Porcini
My friend Cora, who stars in the morel hunting chapter of Fat of the Land the book, passed this recipe along to me from his father's cousin, who lives in Cortemiglia, Italy. She gathers 20 to 50 pounds of porcini annually, so putting up some is a must.
2 cups white vinegar
2 oz water
2 tsp salt
extra light olive oil
1/2 tsp peppercorns per jar
Clean and quarter porcini buttons. Bring vinegar, water, and salt to boil. Cook porcini in batches, no more than 3 minutes per batch. Drain on paper towels and set aside to dry for at least 8 hours. Pack sterilized jars with porcini and peppercorns, then fill with extra light olive oil (use safflower oil if keeping more than 6 months).