Milling of the olives
Olives in the olive oil mill:
Once the olives have been collected, they are taken to the olive oil mill for oil extraction. There are several types of mills, but, by the way of working, we could distinguish two types:
- Traditional: Now practically extinct, which consists of crushing the olives with a large stone wheel (the so-called mill wheels). The pulp thus obtained is placed inside flat containers made with esparto grass and squeezed with a press. Thus, a high quality virgin oil is obtained, provided that the olives have been harvested a few hours before from the top of the tree. This method has been reduced to a few rather testimonial oil mills of limited production.
- Industrial: They are carried out in modern olive oil mills equipped with more technologically advanced machines. Among these we can consider those that carry out a mechanical or physical extraction process and those that obtain oil from chemical procedures.
- Cleaning the olives, as they come from the field, to remove the leaves, soil or twigs.
- Grind the olives to form a compact paste.
- Pressing of the paste.
- Decantation and centrifugation: this removes the oil from the water.
- Filtering: which removes the possible impurities that escape from the previous processes.
The mills that carry out extraction through chemical procedures are in charge of processing those residual oils from the previous process, for obtaining oil from the olive pomace or for treating those oils that, due to their high acidity, are not suitable for human consumption. The refining process involves both the elimination of unpleasant flavours and odors, resulting from the fatty acid fermentation process, and the removal of excess pigmentation. During these procedures the product is subjected to contact with absorbent products and to high temperatures.
Settling tanks | Oil obtained after the spinning process. |
The cultivation of the olive tree
Olives
Benefits of olives | Olive fruit food | Advantages and disadvantages of eating olives |
More information on olive tree