Bolete Mushrooms: Porcini, Bitter and Red-Pored Species

How do you tell porcini from the bitter and poisonous boletes?

Looking down at the cap tells you almost nothing in this group. From above, the bitter bolete and porcini can look essentially identical. You have to turn the mushroom over, cut it and study the stem before any name fits.

Cap color fails the same way with the bronze bolete. Color alone never separates it from bitter or poisonous boletes. For porcini, several characters must agree:

• white to olive pores
• white flesh that does not change in a fresh vertical cut
• a pale, fine net on the stem
• host trees and a region that fit the name

Pink, red or orange pores, rapid staining or a coarse dark net each rule a specimen out as porcini. You do not need all three signs before you reject it.

The red-pored, blue-staining boletes

Three members of this hub are poisonous, and they share the same warning signs. Their pores run yellow to red, the flesh or pores turn blue when you cut or bruise them, and the stem carries a net. The devil's bolete has repeatedly caused forceful vomiting, abdominal pain and diarrhea.

Reports also link the brawny bolete and the bitter beech bolete to gastrointestinal poisoning. The blue reaction is part of each species' description, so it tells you which group you are in. Several red-pored species overlap so closely that a guidebook name or a single photograph cannot tell them apart.

The bitter bolete and the slippery jack

The bitter bolete is harmless to eat. Its taste is the problem, because one cap can ruin a whole pan of porcini. For that reason you clear each bolete on its own before it joins the others in the basket.

The slippery jack grows with pines and belongs to a separate genus. Its family is Suillaceae, outside the Boletaceae. Its likely confusions are other Suillus species, and the poisonous red-pored boletes are not among them. Its glutinous cap skin identifies it and also upsets many people's digestion, so you peel the skin off every cap before cooking.