“Black olive” and “green olive” are not different species, but different stages of ripening of the fruit of the same plant, the olive tree (Olea europaea).
Green Olives
Green olives are harvested earlier, when the fruit is still unripe. They are harder and have a more bitter taste. To become edible, they must undergo a preservation process that usually includes soaking in brine, fermentation or pickling.
Black Olives
Black olives are harvested when they are fully ripe. They are softer and have a milder, sweeter flavor compared to green olives. Like green olives, black olives also need to be preserved before consumption.
Maturation and Preservation Process
The differences in flavor and texture between green and black olives are mainly due to the stage at which they are harvested and their processing methods. Green olives tend to be more bitter due to their higher polyphenol content, which breaks down over time, making black olives less bitter.
Impact on Taste and Use
Because of their differences in taste and texture, green and black olives can be used in a variety of dishes and recipes. Green olives are often used in salads, tapas and as appetizers. Black olives, with their milder flavor, are popular in Mediterranean dishes such as pizza, pasta and tapenade.