Olive Oil has many uses
One of the most common misconceptions about olives is that green and black are separate kinds. They are not. Green olives are simply unripe; leave the same fruit on the tree and it turns purple, then black. Understanding that single fact changes how you taste, buy and cure olives.
Spend time in the olive country of Jaén, in Andalusia — the single most important olive-growing province on earth — and the rhythm of the fruit becomes obvious. The olive starts hard and green, swells to full size, then begins to ripen: green to purple to a deep, oily black. That is the moment the oil comes fully into the fruit and the mills fire up, usually the first or second week of December. Green and black are not rival varieties; they are the same olive caught at two different moments.
Green, purple, black — one fruit ripening
Pick an olive early, while it is still green and firm, and it is denser, more bitter and lower in oil. Leave it to ripen and it softens, sweetens, darkens and fills with oil. Table olives are chosen at whichever stage suits the style: green for a firm, sharp, snappy olive; black for a softer, rounder, mellower one. (One warning: some cheap ‘black’ olives are green olives blackened by oxidation and an iron salt, not ripened on the tree — a real thing to watch for, but a story for another day.) The variety — Manzanilla, Hojiblanca, Picual and the rest — is a separate question from the colour.
Why raw olives are inedible
Straight off the branch, an olive is punishingly bitter — that is the compound oleuropein doing its job of defending the fruit. Every cured olive you have ever eaten has been through a process to draw that bitterness out: brining in salt water, packing in dry salt, or the slow lye cure used commercially. This is the step home cooks with a tree, or a good greengrocer, can do themselves, and it is genuinely satisfying. Time and salt do almost all the work.
Curing your own green olives
The simplest home method is a brine cure. Slit or lightly crack each green olive so the brine can get in, then submerge them in salted water, keeping them weighted under the surface. Change the water periodically over a week or two to leach the bitterness, tasting as you go. When they have lost their raw harshness, pack them into a jar with a fresh brine, a good glug of olive oil on top to seal, and your flavourings — garlic, thyme, a strip of lemon, a little fennel, a shake of paprika. They are edible within days and better after a fortnight. Some old hands leave the sealed jars out in the sun for a week to speed things along.
| Stage | Colour & texture | In the kitchen |
|---|---|---|
| Unripe | Green, firm, dense | Sharp, snappy table olive; low oil |
| Turning | Purple, softening | Milder, rounder; the changeover |
| Ripe | Black, soft, oily | Sweet, mellow olive; full of oil for pressing |
| Home-cured green | Green, firm, seasoned | Your own marinated olives in two weeks |
Practical takeaways
- Green and black are ripeness, not variety — the same tree gives both.
- Green = firmer and sharper; black = softer and sweeter. Choose by mood, not by rule.
- Never eat an olive raw — it must be cured to lose its bitterness.
- Curing your own is easy: crack, brine, change the water, taste, then season.
Green and black olives: common questions
Are green and black olives different varieties?
No. They are the same fruit at different ripeness. Green olives are picked unripe; left on the tree the same fruit turns purple and then black.
Why can’t you eat olives straight from the tree?
Raw olives are intensely bitter because of a compound called oleuropein. Curing — in brine, dry salt or lye — draws that bitterness out and makes them edible.
Which taste stronger, green or black?
Green olives are firmer and sharper; black, ripe olives are softer, sweeter and rounder. Neither is ‘better’ — it depends on the dish.
How long does it take to cure green olives at home?
A brine cure takes roughly one to two weeks of changing the water to leach the bitterness, then they improve further over a couple of weeks in a seasoned brine.
When are olives harvested?
In much of Spain the main harvest runs from about early December for around forty days, though the exact timing shifts with the weather and ripeness.
The green-versus-black confusion is the first thing I try to knock out of anyone new to olives, because once you see that colour is just ripeness you start reading a shelf properly. It also demystifies curing. If you ever get your hands on fresh green olives — from a tree, a market, a friend in the south — crack them, sit them in brine, change the water till the bitterness fades, then season them your way. Two weeks of doing almost nothing and you will never look at a supermarket tub the same way again.
An evergreen guide to olive ripeness and home curing, set in the olive country of Jaén, Spain.