Properly stored in the refrigerator, an open jar of green olives can last for approximately 3 to 4 months past the sell-by date. When left in unopened condition and in a kitchen pantry that is cool and dark, a jar of green olives can last as long as 2 years past its sell-by date.
Although technically a fruit, the inherent bitterness in an olive qualifies it as a vegetable. Olives range in color from green to black and the majority of the ones grown in the United States come from California. Green olives are pitted and then fermented in a brine before being stuffed with a sliver of sweet red bell pepper known as a pimento.