Olive trees have existed for at least 20 million years, as observed from fossil remains discovered near Livorno in the Tuscany region of Italy. It would have been cultivated between 5,000 and 7,000 years ago in different parts of the Mediterranean basin. Olive oil was not only produced in Crete 3,500 years ago, it was also exported.

The Ancient Greeks and Romans planted olive trees everywhere around the Mediterranean, wherever their conquests led them. Trade in olive oil prospered in the Middle Ages because it served every purpose: cooking, soap-making, lighting.

The Spanish conquistadors later planted olive trees in Mexico and in California: all their religious missions had to have enough olive trees, and thus olive oil, for the same reasons, and additionally for their religious rituals.

It is easy to understand how the olive tree and its branches and oil have become charged with symbolism over the millennia, because it accompanied every Mediterranean civilization.

When Adam asked God for forgiveness after eating the apple, He turned away, but gave him three seeds from the Tree of Good and Evil, one of which was that of the olive tree.

In Greek mythology, the olive tree was created by Athena, goddess of wisdom. It was also the symbol of strength, longevity, and hope. It also became the symbol of peace for the Romans. Everyone knows that it was an olive branch that the dove carried in its beak when it finally came back to Noah lost on his ark during the Great Flood.

Hippocrates considered olive oil to be a panacea. It became one of the components of chrism or anointing oil in Christianity. It is still sacred in Catholicism and Judaism; it is the source of light in the Koran, and the olive tree is the holy tree of paradise.

The olive tree now symbolizes global peace, and a representation of the world is surrounded by a wreath of olive branches on the United Nations flag. 

This depends on the different categories, but also on the specific flavor of each olive oil, its smoothness, aromas, and the fruitiness that comes from the particular soil and climate conditions of the area where the olives are grown. These qualities can only be judged by tasting. 

Olive oil is sold in opaque green bottles or in large cans.

There are also certain olive oils that are aromatized with citrus (lemon, orange, grapefruit), mushrooms (fresh porcini, truffles), etc.

Olive oil should always be stored away from light (to prevent oxidation) and at ambient temperature. 

Three-quarters of the fat content olive oil consists of oleic acid, a monounsaturated fatty acid. The rest is divided between polyunsaturates and a little saturated fat. It is also high in the antioxidant vitamin E.

Oleic acid has a favorable effect on bad cholesterol, which it reduces. This is the beneficial action of olive oil, proven – outside of numerous medical studies – by experience: the populations of southern Europe have always had fewer deaths from cardiovascular diseases because of their diet, of which olive oil is the pillar and almost the only fat used.

Olive oil also acts in a beneficial way on the gall bladder and intestinal transit. 

Olives are harvested in winter, when they are ripe. The fruit is sorted and washed, then crushed, ground, and churned in an oil mill until it becomes a paste.

Traditionally, this is first pressed mechanically without heat, giving “extra-virgin” or “virgin” oil from first cold pressing.

The paste is then collected into cakes that are heated and pressed in order to extract the remaining oil.

In an industrial process, olives are centrifuged, producing cold-extraction virgin olive oil.

Whatever the process, the oil is then centrifuged to remove the water it inevitably contains.

European olive oil production is controlled by regulatory criteria that determine the different categories.

The categories are determined depending on flavor (assessed by a jury), degree of acidity, and possible refining. This category must be stated on the label.

. Extra-virgin olive oil: impeccable flavor, acidity lower than 1%.

. Virgin olive oil: almost perfect flavor, acidity lower than 2%.

. Olive oil (no other wording): oil that has not passed the two previous tests and with acidity higher than 2%.

. Refined olive oil:this oil is made from the previously pressed cakes of olive paste.

. Pure olive oil: a blend of virgin and refined oils.

Production rules in the United States are aligned with those of Europe.

Many olive oils have received European PDO status.

In France, these are oils from Aix-en-Provence, Corsica, Haute-Provence, the of Baux-de-Provence valley, Nice, Nîmes, and Nyons.

There are 37 such areas in Italy, 32 in Spain, 16 in Greece, and 60 in the United States (where production is on a small scale and uses traditional methods).