Without drying, a fresh oyster mushroom lasts only 5 to 7 days before it turns bad, according to the University of Kentucky Extension. However, if you dry your mushrooms correctly, you can store them for 6 months or more before eating. Commercial producers dry oyster mushrooms using complex vacuum or dehydrating equipment, but you don't need all that to dry mushrooms at home; just a simple oven and wire rack will work fine.
