Kalamata olives
A dark purple, almond-shaped Greek olive with a rich, fruity, slightly tangy flavor, cured in brine or vinegar until ready to eat. Like all olives, it's inedible straight off the tree -- curing is what gives it both its flavor and its safety.
Buying guidance
Buying them with the pit in generally gets firmer texture and fuller flavor than pre-pitted olives, though pitted is more convenient when they'll be chopped anyway. Taste before adding extra salt to a dish -- the curing brine leaves them quite salty on their own.
Substitutions
- Gaeta or Nicoise olives -- similarly brined and fruity; close substitutes.
- Any brined black olive -- less complex flavor but works for color and salty bite.
- Green olives -- firmer and sharper or more bitter than kalamata; use slightly fewer and taste before adding salt.
Tips & common mistakes
Simmering olives for a long stretch in a sauce can turn them bitter and make their texture mushy -- add them later in cooking, just long enough to warm through, rather than from the start.
Storage
Keep leftover olives submerged in their brine, topping up with a little water or olive oil if needed to keep them covered -- ones left exposed to air in the fridge dry out and can grow a white surface mold within days.