A distinctively green, full-flavored nut containing crunchy meat that has a mildly sweet flavor. They are available salted or unsalted, and shelled or unshelled. The shells of the nut are quite hard and the nuts can be purchased in either their natural tan colored shell or in a shell that has been dyed red for appearance. As the nut matures, the shell splits open exposing the nut and making it easier to remove from the natural casing. Pistachio nuts that do not have the shell split open are not fully matured and should not be eaten. For cooking, 1 cup of unshelled nuts = 1/2 cup of shelled nuts. A substitute for a recipe would be a blanched almond.