Select mushrooms that are consistent in color, smooth, and free of blemishes, lesions, or damp areas. Avoid mushrooms with brown gills, an indication of advanced maturity, save in the case of portobello. The cap should be securely fastened on the foot. In a paper bag, the mushrooms will keep in the refrigerator for a week. On the other hand, it is best not to put them in a plastic bag, which would hasten their decomposition. Furthermore, because they absorb scents readily, it is advisable to keep them away from strong-smelling meals. Mushrooms, raw or cooked, may be readily kept in the freezer in a freezer bag after washing. In the freezer, clean them, set them on a baking sheet or pan, and store them in a freezer bag. Alternatively, cook them dry or in oil before freezing. In the dehydrator, slice them thinly, spread them out on a wire mesh, and dry for 8 to 12 hours in the dehydrator or a low-temperature oven. Canned mushrooms have nearly the same nutritional value as fresh mushrooms, however their salt content might be significant. As a result, it is best to clean them before eating them.