After opening, store any unused mushrooms in the box they came in or in a brown paper bag. Lobster mushrooms will catch some dirt in their cracks and concave caps, so cleaning them takes patience. Use a dry brush to wipe away the dirt. It may be necessary to break the mushrooms apart to get into all the crevices. Cut off any brown spots that might be on the surface. The lobster is a sturdy mushroom, so if you have very dirty ones, they can be quickly rinsed in very cold water. Lobster mushrooms hold their texture after cooking and are wonderful with roasted meats and poultry, or added to pastas, soups, and sauces.