The extraction of olive oil was ubiquitous in the Mediterranean region as early as a few thousand years before Christ: findings prove that olive trees were domesticated in Lebanon around 3,000 BC in order to produce olive oil.
When the Italian city of Pompeii was buried in 79 AD after an eruption of Mount Vesuvius, the lava masses also buried the city’s culinary heritage.
Olive presses appeared during the excavations of the city of Pompeii: To this day, olive presses are considered a reliable way to extract olive oil. Even after almost 2,000 years, the extraction of olive oil has changed little.
Origin of the olive tree
Olive oil was not only used as food: In the southwest of Cyprus, an olive oil factory was discovered during excavations, which was buried in an earthquake in 1850 BC. Olive oil was then used as a base for perfumes, as fuel for smelting furnaces and in the textile industry.
The olive tree is the domesticated species of the oleaster, a shrub with fruits poor in oil. The wild oleaster was most likely domesticated for the first time in the fourth millennium BC in Palestine: By selecting and grafting oleaster plants with the best fruits and characteristics, the olive tree as it is known today developed. Unnecessary green wood was bred away in the process: The olive tree could thus devote itself entirely to the development of its fruits, which now contained significantly more oil than before.
In most cases, olive trees live between 300 and 600 years. Individual specimens can live up to 3,000 years.
The Greeks
Among the Greeks, olive oil reached its golden age: for them, the olive tree was a sanctuary and its fruit, the olive, was a miracle.
If one follows Greek mythology, the olive tree was a gift from Athena, goddess of wisdom.
The olive oil was used in many ways: Olive oil was found not only in food, but also as a skin cream, as a pesticide and as a remedy in medicine. To this day, olive oil has the reputation of preventing many diseases.
Greek athletes rubbed their bodies with olive oil before they trained: a body rubbed with oil was part of the typical image of a Greek athlete at that time.
Moreover, olive oil was enormously important to Greek society from an economic point of view: in his Athenian Constitution, Aristotle went so far as to demand that anyone who cut down an olive tree be sentenced to death. This underlines the important role that olive oil played in Greek society.
Olive oil production
The production of olive oil depends on numerous factors: First, the pruning of the tree is crucial. Although an unpruned olive tree will produce more fruit, it will be much more difficult to harvest. Usually, an olive tree is pruned to facilitate harvesting.
From the end of April to the end of May, olive trees blossom. In the following summer months, the olives grow from the blossoms. Some olive trees bear their first fruit as early as August, but the main olive harvest does not begin until autumn.
Green and fully ripe olives
The olive harvest depends on different stages of ripeness: Olives harvested in September and October are usually still green and provide the basis for a fruity olive oil.
Olives harvested in late November to mid-December are purple to black in color – these are fully ripe olives. If fully ripe olives are processed into olive oil, it is far less flavorful than when green olives are used. Green olives must be laboriously picked from the tree, whereas fully ripe olives fall from the tree and lie on the ground.
Cold pressing
After the olives have been harvested, the next step is the oil mill: first, the olives are washed and freed from leaves and branches. Now the olives are ground, resulting in an olive paste.
In the next step, this paste is heated and kneaded. The temperature is important in this process: One speaks of cold pressing when the temperature of the olive paste does not exceed 27 degrees Celsius during the process. Anything above this temperature is not beneficial to the quality of the olive oil.
During the actual pressing of the olive oil, it was once common practice to spread the olive paste on mats and de-oil it by hydraulic pressing. This nostalgic way of extracting olive oil is rarely practiced today.
Today, the olive pulp is put into centrifuges capable of several thousand revolutions per minute to extract the olive oil. The correct adjustment of these centrifuges requires a lot of expertise and experience, otherwise the taste of the final product suffers.
Olive oil in the modern era
The modern history of olive oil begins shortly after the Second World War: the nutritionist Ancel Keys traveled through Naples, Madrid and Crete. While there, he made a special observation: he noticed that people in southern European countries were much less likely to suffer from heart disease than elsewhere. Ancel Keys attributed this to the fact that people in southern Europe consumed considerably more unsaturated fatty acids, such as those contained in olive oil, than saturated fatty acids. Saturated fatty acids were suspected of clogging arteries. Southern Europeans are therefore less susceptible to heart disease, partly due to their high consumption of olive oil.
Olive oil: a tradition
Keys’ observation caused a stir: Products like olive oil were suddenly back in high demand because of their unsaturated fatty acids.
This trend continues to this day: Especially when it comes to Mediterranean cuisine, olive oil is of great importance. When it comes to olive oil, the quality of the harvest is more important than with any other oil: Even small compromises in harvesting and processing change the final product. In Italy, there are families that have been involved in the production of olive oil for generations: Olive oil production combines traditions with modern technologies.
Cover picture: A salad with olives and chicken nuggets. Served on an olive wood board with an olive oil can.
© Simon von Ludwig, all rights reserved
Main sources: Mueller, Tom: Extra Virginity: The Sublime and Scandalous world of Olive Oil, 2012 Atlantic Books & information from various websites.