Room-temperature Storage

• According to the University of Arizona, a whole eggplant can be kept after purchase for two days at room temperature. Do not, however, cut an eggplant and try to keep it at room temperature, as it perishes very quickly once the skin is cut; store cut eggplant in a refrigerator.
  
  

Refrigeration

• Whole eggplants can last from four days to a week in the refrigerator without having been cut. The Washington Post indicates that the Asian variety of eggplant, which is long and much thinner than the more common variety in the U.S., should be kept in a refrigerator, too, and can last up to five days. Try to store the produce in a slightly warmer section of the fridge, like a crisping drawer, to avoid negative effects of bitter cold near the freezer unit. Look for shriveling as a sign of aging, and use the eggplant immediately.
  
  

Freezing

• For longer-term storage, eggplants can be frozen. First wash them in warm water, cut off the ends and skin it, then slice it into 1/3-inch-thick slices. Boil one gallon of water with one cup of lemon juice. Boil the eggplant slices for four minutes and then spoon out with a straining utensil and add immediately to a bowl of ice water and let it sit for five minutes. PickYourOwn.org states that it's important to keep adding ice when needed to keep the water completely chilled.
  Place the blanched eggplant slices in freezer bags or vacuum bags and seal. The eggplant should be good for up to five months in a freezer bag, or 14 months in a vacuum sealed bag.
  If you like eggplant Parmesan, you can batter dip them, coat them in bread crumbs and then freeze them on wax paper before putting them in freezer bags. Then there's no hassle when you take them out to fry them up.