The Kalamata olive, one of the most popular olives, is named for the Greek region of Kalamata. It is large, smooth and comes in either black or deep purple. Although brined like many olives, the Kalamata olive tends to be slightly less salty, larger and meatier than other olives. The olives come packed in oil. Kalamata olives are used in many well-known Italian recipes like pasta puttanesca and to top foccacia bread. If unavailable, they can be replaced with other similar tasting olives in many recipes.
Capers are small buds from the Capparis spinosa shrub that are pickled or brined in salt and vinegar. They are also a common ingredient for many Mediterranean recipes that call for Kalamata olives. Cooks can substitute the Kalamata olives by just using more capers. While not exactly the same -- the texture is different -- the capers should add a sufficient amount of tangy, salty flavor to the dish.
Maddaleno (Alphonso) olive
This olive comes from a region in Peru called Tacna, on the border with Chile. Although slightly smaller than the Kalamata olive, the Maddaleno or Alphonso olive maintains the same deep purple color. The olive is cured in a wine or wine vinegar brine for approximately five months. The olive is known for its soft, juicy flesh.
Gaeta (Gyeta) olive
The Gaeta olive is a small, blackish purple Italian olive. The olive is presented in two ways: dry salt cured and wet brine cured. Both come treated with olive oil and have a mild, salty flavor. The Gaeta olive comes with its pit intact and is generally used as an appetizer for nibbling.
The Nicoise olive is only grown in the French Riviera, specifically in the Cote d’Azur. These olives are fairly small in size and range in color from dark brown to deep purple to deep black. The olive is cured in two different ways: a dry cure which leaves it black and wrinkled or a salt cure which leaves the skin smooth, but the color a deep purple. Curing can take up to six months.