The Olive life cycle

Young trees

Before planting young trees it is advisable to have a soil sample taken to ascertain what, if any, remedial action needs to be taken to adjust the suitability of the soil to the growing of olives. A slightly acid soil, ph of around 6.5, is advisable along with a good balance of nutrients. The area to be planted should then be deep-ripped, to a depth of around 800mm, to enable good root devlopment. Most olive growers purchase their trees from accredited nurseries which supply them at approximately 600mm tall in small pots. These young trees are planted in differing densities from 250 per ha to over 1000 per ha depending on the variety and if the trees are to be irrigated.

Mature trees

After three years in the ground the trees will bear a small crop of a few kilograms per tree increasing exponentially up to around 50 kilograms per tree and more after five to six years. An olive tree is usually regarded as mature at ten years although their life span can be for well over 1000 years. The olive trees in the garden of Gesthemane, which are still producing, are reputed to be the same trees in the garden at the time of Christ.
An olive tree flowers in spring and the olive is formed from the succesfull pollination of these flowers a few weeks later. The olive continues to grow in size over summer and by mid-autumn to early winter contains the maximum amount of olive oil that is going to be produced.

Harvesting

Some olives are grown for eating and are usually a bigger and flesher olive with a lower concentration of oil than those grown largely for oil. To further confuse matters some olives are suitable for both eating and for the production of olive oil. Olives are picked by hand if they are required for eating, to avoid bruising the fruit, and by mechanical methods or with the use of hand rakes for olives destined to be processed into olive oil.
The mechanical methods can be in the form of pneumatic rakes that knock the olives down from the tree to sophisticated machines that vibrate the trunk of the tree with an automatic catcher to collect the olives and transport them to crates on the back of the shaker. Olives begin to deteriorate from the moment that they are picked so it is imperative that “eating olives” are immersed in a salt and water solution and “oil olives” are put through a processor within hours of harvesting.

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Processing

At Glenlee we use the Pieralisi Fattoria which is a continuous extraction processor. In this Fattoria the olives from an individual variety are first washed, in filtered water, to remove any dirt and/or contaminants before being conveyed to a hammer mill crusher which pulverizes the olives into a thick paste. The paste, which also contains small pieces of the olive pit, is then automatically transported to a malaxer which gently rotates and mixes the paste at room temperature for up to an hour. This mixing breaks open the cell walls in the paste and releases the oil which starts to float to the surface. The paste then passes to a centrifuge where the oil and water from the paste is separated allowing the waste paste to be collected externally and used as a mulch or for animal fodder. The final process is for the oil and water to go through a separator which, as the name suggests, separates the oil from the waste water which is then re-cycled.
The pure extra virgin olive oil is then taken off into stainless steel vats and allowed to settle before being filtered and blended with oil from other varieties. As this process does not involve any chemicals or heat the oil is actually considered a natural fruit juice. Once the oil has settled, after approximately a month, it is then ready for bottling and selling to the consumer.

See our Processing methods in the Gallery section of our Main Menu