Button mushrooms are mild-flavored cultivated white mushrooms in their smallest form, with their caps still closed. Select firm, plump mushrooms that are not slimy or bruised. Store in the refrigerator, unwashed and lightly wrapped in paper towels or in a paper bag, never in plastic.
To clean fresh button mushrooms:
Remove the grit by wiping the mushrooms with a damp paper towel or mushroom brush. For a more thorough cleaning, swish the mushrooms very briefly in water, then pat dry with paper towels.
For other mushroom varieties, see chanterelle, Chinese black, cremini, cultivated, oyster, porcini, portobello, shiitake, straw, tree ear mushrooms, and truffles.