The Oil Mill

The processing of the olives with a continuous cycle system takes place in three phases at temperatures below 25 degrees. The system, produced by PIERALISI ( read more ), is technologically advanced and allows you to control the whole process (from the cleaning of  the olives to the finished product) through regulation and monitoring processes.

impianto frantoio

From the defoliating washer, the olives arrive in appropriately divided portiones to the mill, subsequently into a kneaded paste; at this point the water is added, and the paste is sent to the horizontal centrifuge called the decanter, which exploits the principle of centrifugation at high speed to have a more rapid and effective separation of the paste from its three components: olive residues, water and crude oil. The crude oil and water are sent to the centrifugal separators to extract the oil.
The continuous cycle plant, fully realized in 1998, has enabled to increase productivity thereby reducing the waiting time for the milling, allowing also to work the olives soon after being collected (within 24h), and improving the quality of the oil resulting in a fruitier flavor, with a greater amount of chlorophyll and an  increased allocation of natural antioxidants which help the preservation process.
The kneading (gramolatura) time is greatly reduced, and the olive paste undergoes  minor heating which is a  considerable advantages for the quality of the oil. The extracted oil is then organoleptically more pure than the traditional pressured process ed one, in which the oxidized mats cause an increase in the number of peroxides and acidity.


The transformation process

Processing stages

To get a quality extra virgin olive oil, every moment of the process must be checked carefully.

The extraction process includes several steps:

  • Cleaning and defoliating the olives: once the olives get to the mill after being weighted, they are transfered to a defoliator which through a strong suction is able to separate the leaves and twigs. The olives are then washed by powerful jets of water. At this point the cleaned olives are ready to be processed into the crusher, or mill grinder.
  • Pressing of the olives: the customer is allowed to choose the pressing methods, using either the stone mills for those still bound to tradition or the hammer mill system and grates with  low rpm with double pressing. The grinding of the olives in both cases is done in one continuos step, ensuring a smooth paste suitable for further processes.
  • Kneading the olive paste in stainless steel tanks: operation of continuous mixing of the olive paste to facilitate the aggregation of small particles of oil at a temperature between 20 and 27 ° C for a maximum of 60 min.
  • Centrifugal separation: the kneaded olives are brought to a horizontal centrifuge (decanter) that exploit the principle of specific gravity to separate solids (pulp, peel and seed) and liquid (oil and water);
  • Refining / Clarifying: the final refining of extra virgin olive oil is done through a vertical separator. The oil extracted from the paste should be freed of all extraneous residue, this is done by a further centrifugation. The oil that comes out after the refinery does not appear clear and has a colour ranging from yellow to green (depending on the type of olive) and a distinctive olive scent that you get to feel only in the mill!
  • Storage of crude oil: The oil is stored in stainless steel containers at an average temperature of 15-18 ° C.
  • Filtering of the decanted oil: After a settling period the oil is decanted into a clean container to remove sediments and filtered with a cardboard filter;
  • Bottling of the filtered oil: the oil is bottled in dark glass containers of various capacity at a constant temperature, and stored until selling time.