Update
Strip away the recipes and the marketing and you are left with a small, hard, intensely bitter fruit that no animal in its right mind would eat raw. That an olive becomes either a delicacy or the finest of oils is a triumph of patience — and worth understanding from first principles.
It is easy, surrounded by jars and bottles, to forget how unlikely the olive is. Pick a ripe one straight from the branch, bite it, and you will spit it out: raw, it is punishingly bitter and close to inedible. Everything we love about the olive — the brined table fruit, the green-gold oil — is the result of human ingenuity working on a fruit that gives up nothing for free.
A fruit, not a nut or a vegetable
Botanically the olive is a drupe: a stone fruit, kin to the plum, cherry and almond, with a thin skin, an oily flesh and a hard pit at the centre. The tree, Olea europaea, is an evergreen that lives for centuries and fruits on a stubborn cycle, often heavy one year and light the next. What sets its fruit apart from a plum is fat: the flesh is unusually rich in oil, which is why a fruit ended up as the Mediterranean’s great cooking medium.
Why you cannot just eat it
The wall between tree and table is a compound called oleuropein, concentrated in the skin and flesh, which makes a raw olive fiercely bitter. Removing or breaking it down is the whole art of curing: soaking in water, packing in salt, fermenting in brine, or treating with lye each tames the bitterness in a different way and leaves a different flavour behind. This is why a Greek Kalamata, a cracked green Sicilian and a wrinkled dry-salted black olive taste like three different foods — they are the same fruit, differently persuaded.
| The olive becomes… | How, in a line |
|---|---|
| Table olives | Cured — in water, brine, salt or lye — to strip the bitterness |
| Olive oil | Milled and pressed from the whole fruit, then separated from the water |
| Both, from one tree | Many varieties are dual-purpose; growers choose by ripeness and price |
Oil: the other half of the story
Trapped inside that bitter flesh is the fruit’s real fortune. Crush the whole olive — skin, flesh and stone — into a paste, and the oil can be separated out. Do it gently, without heat or chemicals, and you have extra virgin olive oil, essentially fresh fruit juice with a shelf life. Understanding that oil is squeezed fruit, not a manufactured product, explains almost everything about it: why freshness matters, why it fades, and why the good stuff tastes green and alive. If you want the mechanics, see how olive oil is made.
- An olive is a stone fruit — a drupe, related to the plum, not a nut.
- Raw, it is inedible — the bitterness comes from oleuropein.
- Curing tames it — water, brine, salt or lye, each giving a different olive.
- Oil is pressed fruit — which is why the best of it is fresh and green.
What is an olive: common questions
Can you eat olives straight off the tree?
No. Raw olives are intensely bitter because of a compound called oleuropein, and must be cured — in water, brine, salt or lye — before they are edible.
Is an olive a fruit or a vegetable?
A fruit — specifically a drupe, or stone fruit, related to plums, cherries and almonds. We treat it as savoury, but botanically it is fruit.
What makes olives bitter?
Oleuropein, a natural compound concentrated in the skin and flesh. Curing removes or breaks it down, which is what makes an olive edible.
Are table olives and oil olives the same fruit?
They are the same species and often the same varieties. Many olives are dual-purpose; growers decide whether to cure the fruit or press it for oil.
How is olive oil different from the fruit?
Oil is simply the fat pressed from the whole crushed fruit and separated from its water. Good extra virgin is, in effect, fresh olive juice.
People are often surprised that the two things they know an olive for — the salty snack and the golden oil — are the same fruit handled two different ways. Keep that in mind and you become a better buyer of both. A table olive is a cured fruit, so its texture and cure are everything; an oil is pressed fruit, so its freshness is everything. Neither is a manufactured commodity, whatever the supermarket shelf implies. Both are a hard, bitter little drupe that generations of patience turned into something worth wanting.
An olives101 primer on the fruit behind the jar and the bottle.