After the harvest of the olive from the olive grove, the olive is being transferred to the oil press, from which it goes through several phases, so that the procedure of the receiving of the oil can begin.
The beginning of the procedure starts with the passing of the fruit from special cleaning machines for the leaves, and washing.
The cleaning from the leaves is being done by an automatic machine which removes leaves. This step is necessary because a large amount of leaves when it is being grinded with the fruit of the olive it gives olive oil a bitter taste and a large amount of chlorophyll (green color) which does not help in the preservation of its quality.
Then the washing follows, through which all unnecessary material (soil and dust) in the olive fruit is being removed.
The grinding of the fruit -that is the olive’s chopping into small pieces that form the well-known oil paste- is a significant phase of elision. The breaking of the fruit until some years ago was taking place with 3 or 4 rocks of a variant diameter.
In the last years, the grinding takes place through metallic breakers that rotate the fruit with a big velocity into a fully-pierced drum. During the grinding, there must be given a big attention so that the temperature of the paste does not exceed a certain level of degrees and so that the grinding of the fruit is not excessive because it can be the cause for which the olive oil is going to be bitter.
The kneading of the paste takes place into special, either long or round, mixers. It is important that their walls are stainless and that the paste’s temperature does not exceed 30o C. The kneading must have a duration of approximately 30-45 minutes. Nothing is wasted. The leaves become food for animals and the waste material of the core is an exquisite fueling material even if it has a horrible smell.
The extraction of the olive oil from the oil paste can be done either with pressure or centrifugation. The method of pressure was used from ancient times till today. The technology of the pressings has been through a lot of stages. From the wooden manual pressers of the Roman period it passed to metal, hydraulic automatic pressers that were the main oil extraction methods. Centrifugation is the method that has preponderated lately and is used in 99% in our island. This method uses special horizontal decanters that secure conditions of automatism and high cleaning.
The differentiation and cleaning of the olive oil takes place with special automatic vertical separators that absolve the oil from the water and other strange materials and clear the oil.