The olive tree has its origins in Asia Minor â€“ from the Eastern Mediterranean coast across to modern day Iran . Historians have squabbled for centuries over which people first cultivated the olive and where, but most likely it started around 5,000 B.C. in the cradle of civilisation - Mesopotamia (a vast fertile plain between the Tigris and Euphrates rivers, largely in what is now Iraq ). This area was home to the Sumerians and olive cultivation slowly spread via Turkey and Crete to Egypt , Greece and westwards.
In 1500 B.C., Greece (particularly Mycenae ) was the area most heavily cultivated. With the expansion of the Greek colonies, olive culture reached Southern Italy in the eighth century B.C. and then spread into Southern France . Later, the Romans planted olive trees in Spain and across the entire Mediterranean basin. According to the Roman historian Pliny, Italy had "excellent olive oil at reasonable prices" by the first century A.D. "the best in the Mediterranean!", he maintained. The Spanish, in turn, took the olive tree to the Americas in the 16 th C.
Olive trees have an almost titanic resistance - a vital force which renders them nearly immortal despite heat, drought, cold and fire.
This may explain the widely held belief that olive oil conferred strength and youth. In ancient Egypt , Greece and Rome , it was infused with flowers and grasses to produce both medicines and cosmetics; a list was excavated in Mycenae listing the aromatics (fennel, sesame, celery, watercress, mint, sage, rose, and juniper among others) added to olive oil in the preparation of ointments.
Olive oil has maintained its standing through time as a source of wealth and health, and the olive branch became a universal symbol of glory, honour and peace.
"Sun, stone, silence and solitude" - these are the four ingredients that, according to Italian folk traditions, create the ideal habitat for the olive tree.
Olive trees start to bear useful fruit when they are about 10 years old and can live on well beyond their 500th birthday. Many regions lay claim to the oldest living olive tree, but Crete must be the favourite â€“ there are several villages with trees in excess of 2,000 years old.
The cultivation of olive trees is very straightforward and has remained almost unchanged for centuries:
In spring the trees start to blossom after the cold months of winter. The soil around the trees are fertilised and tilled to improve nutrient levels and moisture retention around the tree's roots. The trees must also be pruned at this time to encourage productive, well balanced growth. Different regions favour different tree shapes: open spherical cups in Greece and Italy or â€œVâ€ shaped in Spain, but the aim is to allow light and air to nurture the fruits as they develop.
Organic fertilisers are best (farmyard and green manures etc.) that can supply nitrogen, phosphorus, potassium and other minerals.
The olive tree can survive in a dry climate. Many trees (especially those up in the hills) are not watered during the summer months because water is scarce. More productive trees near the coast require an adequate water supply and typically, they are watered every 2-3 weeks when the fruit is in its early stages of growth and the pits harden. The fruit continues to grow until the moment when the green colour of the skin fades and reddish spots appear.
During this season the olives grow ripe and they slowly lose their green colour as oil replaces water in the flesh. During this period, the growth and ripening of the fruit requires a steady supply of water, minerals and other nutrients. The soil surrounding the trees is treated at a maximum depth of 20 cm in order to avoid damaging the roots - this treatment allows the mixing of fertiliser with the soil and prepares the soil to receive rainwater and to maintain humidity as long as possible. The simultaneous elimination of weeds helps the tree and prepares the ground for the harvesting.
During the winter (November and December around the Mediterranean ), the olives ripen and their colour changes from green to yellow to violet. The timing of the harvest is critical in determining the characteristics of the oil - an early harvest produces fresh, green, herby oil whilst a later harvest yields a more golden, spicy, sweeter oil. The olive harvest is labour intensive and the best estates pick their olives exclusively by hand. Mechanised harvesting bruises the fruits and causes early oxidation of the oil and is only employed in factory-scale not common at all because it does not work well. Almost all operations are totally manual and that is the most important reason for the higher prices of olive oil.
Olive oil keeps better in large containers (rather like champagne), so most producers keep their oil in airtight stainless steel tanks or big earthenware jars and bottle it as and when it's required. Unlike wine, olive oil does not improve with maturity. Properly stored, it will keep for about 18 months from harvest time so make sure you check the best before date on the bottle. Depending on how fastidious the producer is, they may put anything between 6 months and two years on the bottle. Once opened, extra virgin olive oil should be used within two months.