How is extra virgin olive oil made?
Extra virgin olive oil is a natural juice from olives, a product with properties that make it ideal for cooking and excellent for our health.
Its production has evolved a lot in recent decades, and continues to do so, but we would like to tell you here how extra virgin olive oil is currently produced.
The official definition
The regulations define extra virgin olive oil as “oil extracted exclusively by mechanical means, with a maximum acidity of 0.8%. It is an oil with irreproachable organoleptic qualities and has more health-giving qualities than any other type of olive oil.”
Caring for the olive tree and the olives
If we want to obtain extra virgin olive oil, it is important to take care of the olive tree throughout the year. The harvesting of the olives and the production of extra virgin olive oil are the final phase of the whole process, which takes place during the previous seasons. During this period, the weather and good care of the olive tree, with activities such as pruning, are fundamental for the good development of the fruit, the olive.
In the area covered by the Designation of Origin Estepa we work with two totally sustainable production systems: integrated production and organic production. This is fundamental to guarantee the care of the olive tree and the correct conservation of the natural environment:
- Integrated Production
- Organic Production
Harvesting the olives
One of the key factors in the production of extra virgin olive oil is the harvesting of the olives. It is essential that the olives arrive in good condition at the mill in order to be able to extract the best extra virgin olive oil.
The olives harvested to produce the extra virgin olive oil protected by the Designation of Origin Estepa must meet the following requirements:
- Early harvesting: The olive is harvested when it is green or in veraison, turning from green to purple
- Condition of the olive: The olive must be healthy and in its optimum state of ripeness, clean and free of bruises.
- Picked from the tree: The olive must always be picked directly from the tree. Olives harvested from the ground are of inferior quality and are not valid for the production of our extra virgin olive oil.
There are several ways of harvesting the olives:
- Vareo: The branches of the olive tree are beaten with a stick until the olives fall. In the territory of the Designation of Origin Estepa, this technique is becoming extinct and is rarely used.
- Vibration: A mechanical system is used to vibrate the tree so the olives fall onto the “fardos” (harvesting nets), and from there the olives are taken to the trailers for transport. This is currently the most widely used system because it is the fastest and guarantees that the olives are preserved in the best conditions.
Transport and unloading
Both harvesting and transport must be carried out with the utmost care to ensure that the olives are not damaged. The fruit must be transported from the olive grove to the mill on the same day as it is harvested, as the speed with which the process is carried out is a determining factor in the quality of the final oil.
Once the olives are in the mill, they can be separated according to variety. The masters and technicians of the mill associated with the Protected Designation of Origin Estepa make an initial selection of the olives that will be used to make extra virgin olive oil.
From now on, a continuous process takes place which, if carried out under the best conditions, will produce an extra virgin olive oil of the highest quality.
Washing and weighing the olives
On arrival at the mill, the olives are separated from both the leaves and the branches by fans.
After this initial cleaning, the olives may undergo a brief washing, if deemed necessary by the mill master, before being weighed. The weighing of the olives is very important, as each farmer must know the quantity of olives that has been delivered to the mill.
Milling and grinding
The next step is milling. This is the process in which the olives are crushed in order to extract the oil.
In the area covered by the Designation of Origin Estepa, stainless steel mills are used to tear the cell membranes of the olives, leaving the oil globules free.
The olives must be milled on the day they are harvested to prevent them from deteriorating. This is the only way to obtain a quality extra virgin olive oil.
Beating the pulp
The pulp from the milling process is then beaten in order to collect the maximum number of drops of oil dispersed in the pulp.
In the entities covered by the Designation of Origin Estepa, the beating of the pulp is carried out at a cold temperature, specifically below 27 degrees Celsius. The process is carried out at a low temperature, which is essential to guarantee the quality of the extra virgin olive oil.
Olive oil mills normally have numerous mixers, which generally consist of semi-cylindrical horizontal vats with an outer chamber through which hot water circulates to keep the pulp at the required temperature.
Inside the mixer, the olive paste is kept in motion in a device that rotates around a shaft.
Centrifugation of the pulp
Centrifugation is the phase in which the oil is separated from the olive by the effect of centrifugal force, which increases the differences between the specific densities of the oil and the solid matter together with the vegetation water.
This operation is carried out in a horizontal centrifugal decanter. As the oily phase coming out of the centrifuge may contain solid particles, it is advisable to have a vibrating sieve at the oil outlet to separate the small pieces of pulp or bone.
Centrifugation of the liquids
Next, once the oil has been separated from the solid part and a large part of the vegetation water, we subject it to a new centrifugation, where the oil is cleaned, separating it from the moisture that may remain from the previous phase, and removing fine solids considered as impurities.
After centrifugation, the oil is decanted, a process that separates the oil from the water and the impurities (small olive particles) that have not been separated in the centrifugation processes.
Finally, the oil reaches the cellar, which consists of stainless steel tanks that can hold between 25,000 and 250,000 kilos of oil and protect it from light and air. The temperature in the cellar is between 15 and 18º. The conditions in which the oil remains in the cellar are important for the quality to remain intact.