Mushrooms should always be washed before cooking. All their parts are edible, including the caps, gills, and stems. Oyster mushrooms are tasty and pair well with a variety of foods. Use them in meals like soups, stews, pasta dishes, and stir-fries. The best way to store oyster mushrooms is to place them in a plastic bag or on a plate covered with plastic wrap in the refrigerator or place the mushrooms in a paper bag in the refrigerator. Fresh mushrooms are likely to stay good for about 4 to 7 days. Freeze any fresh mushrooms that you don't plan to use right away. Boil them first for 1 to 3 minutes. Then drain thoroughly, seal in airtight bags, and place in the freezer.