The hallmarks of a good extra virgin olive oil can be categorised into fruitiness, bitterness and pungency.
The fruitiness should be reminiscent of fresh green or ripe olive with pleasant grassy notes and herbaceous character. Riper olives will produce oils with rich buttery and soft nutty notes.
The sign of a good oil is a bitterness on the tongue which is characterful of the fresh pressed fruit. Olives harvested early in the season tend to show a greater degree of bitterness giving the oil a satisfying bite.