In order to retain the full flavour of mushrooms, it is best not to peel or wash them, but simply to wipe them with a damp cloth and then dry them. If the stalks are tough, stringy, or maggoty, they are removed. Otherwise, the base of the stalk is sliced off. Only the mushrooms that become sticky in damp weather (including certain boletus mushrooms) and those with a bitter outer skin (cortinae and pholiotae) are peeled. THe fleshy tubes of boletus mushrooms are removed if they are too spongy, and the gills of certain other mushrooms are trimmed if they are too ripe. If absolutely necessary, the mushrooms may be washed very quickly, but never allowed to soak. Varieties such as morels, which have a cap that is pitted like a honeycomb, are cleaned with a small brush.