This section is from the book "Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc.", by George Francis Atkinson. Also available from Amazon: Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc..
By Mrs. Sarah Tyson Rorer.
As varieties of mushrooms differ in analysis, texture and density of flesh, different methods of cooking give best results. For instance, the Coprinus micaceus, being very delicate, is easily destroyed by over-cooking; a dry, quick pan of the "mushroom bells" retains the best flavor; while the more dense Agaricus campestris requires long, slow cooking to bring out the flavor, and to be tender and digestible. Simplicity of seasoning, however, must be observed, or the mushroom flavor will be destroyed. If the mushroom itself has an objectionable flavor, better let it alone than to add mustard or lemon juice to overcome it. Mushrooms, like many of the more succulent vegetables, are largely water, and readily part with their juices on application of salt or heat; hence it becomes necessary to put the mushroom over the fire usually without the addition of water, or the juices will be so diluted that they will lack flavor. They have much better flavor cooked without peeling, with the exception of puff-balls, which should always be pared. As they lose their flavor by soaking, wash them quickly, a few at a time; take the mushroom in the left hand and with the right hand wash the top or pileus, using either a very soft brush or a piece of flannel; shake them well and put them into a colander to dry.