Whatever kind you buy, choose eggplants that have smooth skin, shiny and free of blemishes.
Eggplants come in many different shapes and various colors. The most common has a dark purple skin and is elongated, and plump at the bottom end. There is also the white eggplant, but I find that species tough and with a lot of seeds. Whatever kind you buy, choose eggplants that have smooth skin, shiny and free of blemishes. The body should be firm and crispy to the touch, not spongy, the stem long and as green as possible. A green stem is an indication that the eggplant has been harvested recently. When you cut into an eggplant, the seeds should be fresh and white; if they are dark, the eggplant has been around for while, and it will be more bitter. To remove some of the bitterness, slice the eggplant and layer it in a colander, sprinkling each layer with coarse salt. Put some weight on the slices, and allow them to drain for an hour. The salt will extract liquid from the eggplant, and with it some of the bitterness. Rinse the eggplant, pat dry, and proceed with the recipe. To clean the eggplant, cut off the stem and peel it. If the skin is fresh and shiny, I take off the eggplant skin in alternating strips, like a zebra, leaving about half of the skin on.