Olive-oil > Production


Olive Oil production is based on the extraction of the oil from the olives by the least possible agressive mechanical methods to best preserve the features and properties of the resulting olive juice.

This is the most intensive and effort demanding work of the ones done during the calendar year in the cultivation and care of the Olive Tree and it is also the one that is most directly related to the final price and quality of the resulting Olive Oil.

In order to produce 1 liter of Olive Oil, we need between 4 and 5 kilograms of olives, making it a yield of 18% to 24% of oil weight with respect to the olive weight needed to produce it.

At this point it is necessary to remind the reader that any type of oil, including olive oil, is a fatty liquid with smaller density than watter and insoluble in it. Olive oil’s density is 0.918 kg./l, that is, 1 kilogram of Oil has a volume of 1,0893 liters.

Olive Oil is different from other natural products like wine, in the sense that it does not improve with time. On the contrary, it is advised to consume it as soon as possible within the year of production. Regarding production, the sooner the Olives are processed once collected, and the less thermally and physically agressive the process is, the better the quality of the final product. Some Oil varieties, like the Picual variety are more stable and can be stored up to 18 months without loosing their sensorial features.

Virgin Olive Oils do not suffer any chemical, thermal or agressive physical process in their extraction. This gives us a clear picture of the differences in quality between Virgin Olive Oils and refined of pomace oils.

The production process begins with the harvest of the olives, hand-picked (“milking”), “vareo” (hitting with a long flexible stick) of by means of mechanical vibration. The next step is its transportation to the Almazara (Olive Mill) where the oil will be extracted.

In the Olive Mill, the olives are separated from the branches, leaves and rocks that come with the olives from the harvest. It is then washed before grinding or crushing it. Both the grinding and the crushing break the olives and transform them into a paste that can be processed to extract the small oil drops contained in it.

Depending on whether the oil extraction system is traditional or industrial, the paste will be processes by pressure or by spinning:

Traditional system, by pressure (discontinuous classic plants). The crunched paste is introduced between esparto disks and pressure is exerted on it to extract an oily juice (admixture of oil and water), that is decanted to obtain the oil by flotation, due to the difference in densities.

Three step continuous system, by spinning (Three step continuous plants): 1 liter of water is added to each kilogram of paste and then introduced in a horizontal spinner, where the solids are separated from the oily juice. The juice is then moved to a vertical spinner in which the remaining (vegetation) water is separated from the oil.

Two step continuous system, by spinning (two step continuous plants): similar to the previous process but instead of using new water at the beginning, the vegetation water is recicled and added to the paste.

The continuous system, more modern and currently used, avoids the storage of the olives, as they are processes as they arrive in the Olive Mill. This results in a higher quality oil and also in a better performance of the production process and a spotless control of the hygiene and cleanliness of the mill. The two step process does not introduce fresh water in the process and allows for a higher amount of polyphenols in the Oil.

Once produced, the Oil has to be storaged properly in cellars, protected from the light, smells and other agents that can affect its quality, at a controlled temperature and in inert containers to avoid oxidation. It is usually stored in stainless steel containers until the time it is bottled.

Onces bottled, air, light and heat affect olive oil, so it is advised to preserve it properly closed, at room temperature and protected from direct sunlight.