Olives are sold pitted and unpitted. Although purchased pitted olives are more convenient to use in cooking than unpitted olives, putting causes more of the olive to be exposed to the brine. This can cause the flesh to become softer and yield a different flavor. One way to remove a pit from an unpitted olive is to gently crush the long side of the olive with the heel of your hand, then pull out the pit. Here are some of the more flavorful olives available:
Alphonso: A huge, deep-purple olive from Chile with soft, meaty flesh and a slightly bitter, sour taste.
Arbequina: A green, brine-cured olive with a slightly bitter taste.
Cerignola: A huge, green or jet-black brine-cured olive with a lemon-apple flavor. This one is difficult to pit.
Gaeta: A small, reddish-brown olive with a slightly earthy flavor.
Kalamata: A greenish-black-purple, brine-cured olive with a pungent, lingering flavor.
La Catalan: A brine-cured Spanish olive that's marinated with curry, celery, and pepper. It has a crisp, dense flesh and an assertive curry flavor.
Nicoise: A small, brownish-purple, brine-cured olive that's fruity and juicy, but not oily.
Nyon: A black, dry-roasted, tender olive with a slightly bitter flavor.