Dried Oyster mushrooms have a shelf life of up to a year in a proper hygienic condition and can be used as a replacement for fresh mushrooms. Always soak dried mushrooms in very hot water for 20 minutes or until soft before using.. Use mushrooms and strained broth in soups, sautées, sauces, stir-frys or in any dish calling for fresh mushrooms. Due to Sun-drying Vitamin D content is improved.