I've tried pickling beech mushroom in a sichuan-style brine several times and have been consistently disappointed with the end result. they just don't get hot. i'm toasting the peppercorns, grinding them into a powder in a mortar and pestle, and then adding the powder to the boiling brine. I've also put diced chili peppers and still no heat.
today i sautéed three packs of white beech with garlic and three red chili peppers. again, no heat. is it possible that these mushrooms don't take on spice?