Select fresh, firm, even-shaped mushrooms with no bruises or visible moisture on the outside. Avoid buying slimy mushrooms.
When buying loose mushrooms, try to selecting ones that are close to the same size to ensure similar cooking times. Store these mushrooms in a brown paper bag in the fridge to maintain their taste and texture.
If buying packaged mushrooms, check to make sure there is no excess moisture inside the package. Packaged mushrooms keep well in the refrigerator, but once opened they should be transferred and stored in a brown paper bag, as they will breathe better and stay firm longer.
Mushrooms are best when used within a few days of purchase, but can be kept in the fridge for up to one week.
To Freeze Mushrooms; simply clean and slice them, and then place them carefully in a freezer bag. Blanching makes them tough, and is unnecessary if you intend to freeze them for less than 3 months. If you plan to freeze mushrooms for a longer period, sprinkle them with lemon juice diluted with water and then blanch them for 2½ minutes. Add them to recipes from frozen.