Storage: Store dried reishi mushrooms in an air-tight container or zip top bag in a cool, dry, dark cupboard.
Shelf Life: Dried mushrooms will retain their flavor for at least a year, but likely far longer.

Reishi mushrooms are generally steeped in boiling water to make reishi tea, rather than consumed themselves. Though the basic tea recipe is quite bitter, it can be made more palatable through the addition of herbs, fruit juices, sweeteners and other ingredients.
Reishi Mushroom Recipes