Off the coast of Haifa, under a few metres of Mediterranean water, there is a pit packed with crushed olive stones. Around it sit stone basins and the remains of woven baskets that were used as strainers. The village that dug that pit stood on dry land roughly 6,500 years ago, before rising sea levels drowned it and buried it under marine sand, which is the only reason any of it survived. It is the oldest direct evidence of olive oil production found anywhere in the world.
The site is called Kfar Samir, and it makes a point that catches most people off guard. The olives being crushed there were almost certainly wild. Nobody had domesticated the tree yet. Olive oil is older than the olive as a crop: the industry came first, the orchard came second.
A fruit nobody could eat
Start with the reason. An olive straight from the branch is close to inedible. It contains oleuropein, a bitter phenolic compound the tree produces to keep insects, birds and microbes away from the fruit while the seed matures. Bite into one and the bitterness is sharp enough to feel like an argument. Every table olive you have ever eaten has been cured in brine, salt, water or lye to break that compound down.
So the fruit itself was never the attraction. What made the olive worth the trouble was what came out of it under pressure. And with wild trees, the trouble was considerable. The wild olive, or oleaster, is the ancestor of every cultivated variety, and it carries fruit under 8 mm across containing roughly 5 to 15 percent oil by weight. A cultivated olive today runs 10 to 20 mm, at 15 to 30 percent. Filling a jar from wild trees meant handling an enormous quantity of fruit for very little return, which tells you something about how much that oil was worth to the people doing the work. It was food, it was lamp fuel, and unlike almost everything else they grew, it kept.
What the Carmel coast preserved
The submerged Neolithic villages along the Carmel coast are unusually informative because the water saved them. Sealed under sand in oxygen-poor conditions, organic material that would normally rot away, such as basketry, wood and olive pulp, stayed intact for seven thousand years.
At Kfar Samir, occupied somewhere between about 7,600 and 7,000 years ago, everything points to oil: stones crushed and separated from their pulp, pressing waste concentrated in pits, basins and strainers alongside. At Hishuley Carmel, a neighbouring site roughly 500 years younger, the picture changes. There the pits are whole and unbroken, sitting in stone basins near the shoreline. That is the signature of curing rather than crushing, and the earliest known table olives. Sea water was right there for the salting.
The order is worth pausing on. On the evidence we have, people worked out how to get oil out of an olive several centuries before they worked out how to make the olive itself pleasant to eat.
How a wild tree became a crop
Making oil is one question; farming the tree is another, and the answer arrives later. Current thinking places the domestication of the olive at around 6,000 years ago in the Levant. Chloroplast DNA narrows the cradle further: roughly 90 percent of the world's olive cultivars carry one of three closely related maternal lineages that appear to originate near the present border between north-western Syria and south-eastern Turkey.
Wild olives had been in the region far longer. Through the ice ages, oleaster populations held out in three refuges: the Near East including Cyprus, the Aegean, and the stretch from southern Spain to Morocco. They spread outward again as the climate warmed, helped along by people clearing woodland.
The clearest archaeological sign of deliberate cultivation is a tree growing where it has no business growing. At Tel Tsaf in the Jordan Valley, well outside the wild olive's natural range, excavators recovered a substantial quantity of charred olive wood dating to about 7,000 years ago. Someone had planted those trees. It is one of the earliest documented cases of fruit-tree horticulture anywhere in the world.
After that, the fruit begins to change. Olive stones recovered from Bronze Age sites shift shape abruptly, from round towards elongated, the physical trace of human selection. Whether that selection happened once and spread, or several times independently in different corners of the Mediterranean, is still genuinely contested among researchers.
Why every olive variety is a clone
There was a problem to solve before any olive grove could exist. Plant an olive stone and you do not get a copy of the tree it came from. You get a new individual with its own unpredictable combination of traits: usually worse, occasionally better, almost never the same. Finding a wild tree with heavier fruit and more oil is useless if you have no way to reproduce it.
The answer was to stop using seed. Olive domestication was carried out through vegetative propagation: taking cuttings, and later grafting a chosen variety onto hardier rootstock. Grafting leaves nothing behind for archaeologists to dig up, so the earliest firm records of it are written ones, from Greek and Roman authors. But the practice is the entire basis of olive growing, and it carries a strange implication. An olive variety is not a breed. It is a clone: one original tree, copied by hand, over and over, for as long as growers keep taking wood from it.
This is also why domestication left such a faint mark on the olive's genetics. The tree is slow, and a population can take more than a century to turn over, so relatively few generations of selection separate a cultivated olive from a wild one. Cultivated trees have also gone on exchanging pollen with wild ones the entire time.
That lineage is still maintained exactly the same way. The varieties growing in Istrian groves today are propagated by cutting and grafting, as they were in antiquity. That includes indigenous ones such as Istarska bjelica and Buža, alongside introduced varieties like Leccino. It is why single-variety extra virgin olive oils taste so distinct from one another, and why comparing them side by side is the most direct way to understand what a variety actually contributes. Our Buža is a single-variety oil with a rich aroma and balanced fruitiness, bitterness and piquante taste, carrying apple, tomato, almond and green grass. That character comes from a genotype somebody, at some point, decided was worth keeping.
By the Bronze Age, olive oil had stopped being a village craft. Palaces were storing it in vast jars, scribes were counting it, and ships were carrying it across open water in quantities that required accounting.
Next in this series: Part 2 looks at how olive oil became one of the ancient world's first international commodities, from Minoan storerooms and Linear B tablets to the cargo of a Late Bronze Age shipwreck.