Collecting & Preserving Mushrooms from the Wild
If you find that the mushrooms you have par-boiled are still bitter then discard the first water and boil them again in new water. That usually works. Occasionally, I had to do this 3 times to get rid of all the bitterness.
Sarcodon imbricatus (Hawk Wing): It has a strong flavor and can be bitter, especially the older mushrooms. They are also hard to digest for some people. These problems can be improved by par-boiling. Slice the mushrooms and add to salted water for 10 to 15 minutes, then drain them. You may need to par-boil them again in a second water. If the bitterness is now gone you can add them to a recipe. As with other hard to digest mushrooms, only eat a small amount the first time you try it, and wait for a day before eating it again, just to make sure there is no reaction.
Laetiporus conifericola (Chicken of the Woods): Use caution since some people are sensitive to this mushroom or find it hard to digest. Par-boiling can improve its digestibility. It makes an excellent mushroom soup, but it requires long, slow cooking at low temperatures. These beautiful mushrooms are orange shelves with yellow margins and pores. Be sure you only cut the young, tender margins of the mushroom for eating or it can be too woody.
Sparassis radicata (Cauliflower Mushroom): This mushroom resembles a pile of pasta or a large cauliflower. It is best when treated as if it was pasta or used in casseroles or stir-fry dishes. If it taste bitter par-boil it first. Then it can be cooked and frozen for use later. Sparassis is excellent separated into sections, dipped in batter, and deep-fried. Also use it in sauces and soups when finely chopped. The texture can be chewy.