Olive Oil Production

The best olive oils hold a certificate by an independent organization (not regulated or financed by the industry) that authenticates the stone ground and cold pressed extraction process.

In this process, olives are first harvested by hand at the proper stage of ripeness and maturity. Experts feel that hand harvesting, as opposed to mechanical harvesting, enables olives of the same size and ripeness to be picked and eliminates bruising of the fruit which causes tartness and oil acidity.

The olives harvested are transferred daily to the mill. This is very important because this daily transfer minimizes the time spent between picking and pressing. By contrast, other extra virgin olive oil producers are known to transfer the olives by multi-ton trucks over long distances that expose the fragile fruit to crushing weight and the hot Mediterranean sun, which causes the olives to begin oxidizing thus becoming acidic.

Once at the mill, the leaves are sucked away with air fans and the olives are washed with circulating potable water to remove all impurities. The stone mill and cold pressing technique is used for the extraction of our extra virgin olive oils.

The first step of extraction is crushing the olives to form a paste. The oil, comprising 20% to 30% of the olive, is nestled in pockets within the fruit's cells. The olives are crushed in a mill with two granite millstones rolling within a metal basin. Crushing and mixing the olives releases the oil from the cells of the olive without heating the paste. A side shutter on the mill's basin allows the mixed olive paste to be discharged and applied to round mats. The mats are stacked and placed under the head of a hydraulic press frame that applies downward pressure and extracts the oil. The first pressing yields the superior quality oil, and the second and third pressings produce an inferior quality oil. 

In addition, this form of the oil contains "polyphenols", substances that have been found to be powerful antioxidants capable of protecting against certain types of disease. The polyphenols are not the only substances in the olive with health-promoting effects, but they are quite unique when compared to other commonly used culinary oils such as sunflower, soy, etc.. It is these polyphenols that really set extra virgin olive oils apart from any other oil and any other form of olive oil. The more refined the olive oil is, the smaller the quantity of polyphenols.

Some producers use time-saving and labor-saving centrifugal presses that are more damaging to the oil and its flavor and, thus, they do not receive the certification earned only by producers using the traditional cold pressed technique preferred by The Olive Tree World.

The olive oil is then pumped into a separator in order to separate the oil from the water and small solid particles. During the process, the temperature must be maintained between 16-28 degrees Celsius to prevent thermal deterioration of the oil.

The result of the producers' efforts is a cold pressed extra virgin olive oil with high quality standards and organoleptic characteristics, which give the oil its health-protective and aromatic properties.