The skin of an eggplant should be glossy, not dull, and the eggplant should be fairly firm. If you press it lightly with your thumb, if it gives a little and then springs right back, it’s ripe. If the indentation stays, it is overripe. If there’s no give at all, the eggplant was picked too early, but even that is better than overripe.
Rinse the eggplant in cool water, washing away whatever may be on its surface. Dry with paper towel or clean dishcloth.
Eggplant can be kept for a couple of days outside of the refrigerator but only if the skin is not cut. The eggplant will perish quickly if the skin is punctured and left at room temperature. Uncut eggplants will stay fresh for about a week in the refrigerator. Be sure to place them carefully without cutting or scrapping the skin. Storing eggplant in the vegetable drawer keeps it away from the freezer compartment so that it stays cool without freezing. Use the eggplant as soon as possible and within 5 days of refrigeration to avoid shriveling and aging.
Eggplant is best preserved through pickling, oil-packing, or freezing.