Olive brine, also called olive juice, is the salted liquid olives are packed in during curing and storage; it takes on a savory, salty, tangy flavor from the olives themselves. Cooks use it to add saltiness and olive flavor to sauces, dressings, dips, braises, and stews, and it is the signature ingredient in a dirty martini, where it replaces or supplements vermouth. Its exact flavor varies with the olive variety and curing method: brine from Kalamata olives tastes different from that of Manzanilla or Castelvetrano olives, and some producers infuse it further with garlic or herbs. Because it is salty, add it gradually and adjust the rest of a dish's seasoning accordingly.