Olive oil production process

The process of making extra virgin olive oil, from harvesting to the end of the process, has remained virtually unchanged over the years. Every day, new technologies have been applied that have improved times or performance, as well as the quality of the work, but the steps that are followed from the field to the Almazara have been subject to little change.

This process consists of several phases: harvesting, blowing, washing, grinding, smoothing or spinning, and if applicable, filtering. Next we will stop at each of them, to understand them a little better:





The process of selecting and harvesting the olives is usually carried out during the months of November and December of each year. It is a process that depends directly on external factors such as climatology, since, depending on the sun, cold or rains, this first step of the process may have to be advanced or delayed in order to catch the fruit in its optimal state of maturation, which will guarantee us a higher quality oil and better organoleptic qualities.
Beyond the climatic factors, from a time to this part has become usual to advance or voluntarily delay the harvest, in order to produce an “taylor made product”, since the so-called early olives (or collected a little before reaching their exact ripening point) will offer us a slightly more intense or bitter oil , with nuances of flavor and color more greenish or bitter. Some of these oils are called early oils, green oils, etc., and are highly appreciated, not only because they are the first campaign oil, but because the first green olives, we will not be able to enjoy them again until the next campaign.

On the other hand, and according to the same logic, there is the possibility of picking the fruit a few days later from its ideal ripening point, in order to obtain oils such as so-called “mature oils”, that is, a product where we have lost some of the characteristic nuances of bitterness or potency to achieve sweeter and softer flavors.

This last step should be done with the utmost care, since the olives once they reach their ripening point are at risk of “chopping” with which we would obtain a lower quality oil with worse organoleptic qualities.

There are various techniques of olive collection, although here we will stop at the techniques called “flight”, which as the name suggests, will consist of taking the olives directly from the olive tree, and never those that have fallen to the ground, which would offer us a product of very low quality. We must bear in mind that once the olive has been cut from the tree, it has stopped feeding and its conditions would no longer be optimal for obtaining a good oil. Among the techniques used we can highlight:

Recolección aceitunas


It is usually used for olives for direct consumption (table olives), and consists of manually collecting, one at a time, the olives from the tree.
Shaking: This technique has a certain risk of damaging the tree, as it consists in subjecting the trunk and thicker branches to strong shakes to get off the fruit of the branches.
Vareo: Today it is one of the most used. It consists of varing or moving smoothly and prolongedly to the branches of the tree until the already ripe olives are falling. These olives are collected in flying nets to prevent damage.

Regardless of the method used, it is vitally important to immediately transport the olives to the Almazara, as this ensures that the qualities of the olive are not altered. In the old days we saw oils where parameters such as acidity were excessively high and substantially worsened their quality. This is one of the parameters that are directly altered depending on the time that passes from the collection of the fruit to the production of the oil. At present we can say that the usual practice is that they never exceed 24 hours from collection to processing.

It should be noted that in transport healthy olives must be perfectly separated from defective olives, so as not to mix them and alter the quality of the final product.


Once in the mill, and selected the best olives that will guarantee us an extra virgin olive oil of the highest quality, they are subjected to a process called blowing.

It is a very simple step in which the olives travel by a conveyor belt subjected to the force of powerful fans that will take care of removing all the leaves, stems, sticks and any other impurities, so that we only have olives left ready to be washed.

At this time, so-called “weighing” of the olive is usually performed, and sampling is carried out for the relevant laboratory tests.

Once the unwanted remains are blown, the olive is subjected to washing. It is a simple process in the jets of pressurized drinking water are responsible for washing the fruits, removing dust, mud and any other substance that could have been attached.

Soplado y lavado de aceituna


Grinding is the procedure by which we will break and crush the olive (with its bone included) in order to extract the oil from inside.

Historically, the so-called Stone Mills were used, which consisted of a group of 3 or more large and conical stones that rotated on an axis passing over and over on the olives until they were crushed to the maximum and collect the resulting juice.

This procedure is very little extended today as its profitability is far from the parameters of what is desired. It is no less true, that there are still mills where oil is made with this method almost by hand and offering a product of very high quality.

The most common method today is the so-called Metal Mill or Shredder. This can be Hammers, Toothed Discs, or Striatum Cylinders.

Any of the methods used guarantee maximum extraction of dough or paste. Once the grinding process is finished we have obtained a paste composed of several elements: oil, olive pulp, broken and crushed bones and water.

Molienda de aceituna


At present, this phase of oil production could perfectly be called spinning, due to the machines used for its execution, but it is really a name, in my opinion, very unsophisticated, so that historical name of smoothie is still maintained.

Well, throughout this process what we are going to achieve is to dismember or separate what interests us from what we do not, from that dough or paste that we have obtained during grinding. Machines called blenders or centrifuges (continuous system) are responsible for performing this step. In short, it is only a few containers where the paste is housed and is subjected to a smoothie or turns to a certain number of revolutions controlled where the oil will be separated from the rest of the dough.

It is very important to note here that during this process, the temperature is absolutely controlled, since it should never exceed 30o Celsius, which would be the time when we would start damaging the product. We will all remember traditional phrases like “cold-crafted” or “cold pressure”.

Currently, this tells us that the oil has not exceeded the limit of 30o throughout its entire production process. If we exceeded this temperature, we would favor the oxidation process, which would inevitably lead to a deteriorated product. In addition to losing many of the properties of our oil.

Once the paste is spinning, 3 layers are obtained at 3 different levels, inside the centrifuge: In the lower layer is stored the Orujo (solid mass of pulp, skin and olive bone), on it, the Alpechín (a mixture of organic matter and water) and in the highest part, the Oil.

This process is due to a purely physical procedure. Each of the 3 elements is separated from the other 2, by the difference in densities and weights between them. In this way we have been able to separate the oil from the other components.

Centrifugado aceite


Once we have obtained the olive oil (only by mechanical procedures), we would be left to submit them to the filtering process. In general the vast majority of olive oil that we find on the market have a clean and bright appearance. This is due to the filtering process using different procedures (fabrics, earths…..). some of these filtrates are called polishing and it is a second filtering step where we will give the product a greater sense of cleanliness and transparency. It is a matter of tastes to opt for more or less clean or shiny oils.

But there is another possibility, and they are so-called branch oils or unfiltered oils. These oils offer a more cloudy appearance, and are due exclusively to the absence of filtering. They therefore preserve the press remains or what we might call grounds or part of the pulp of the olive.

Logically they are thicker and tend to be more potent in their taste. They have both defenders and detractors, and in my opinion, it’s just a matter of taste. This type of oils retain organoleptic properties that once filtered we will lose, and in return they usually present a darker layer that we can see at the bottom of the container when it has rested.

Filtrado aceite de oliva

In short, decide whether they consume it filtered or branched, but do, always consume extra virgin olive oil, its flavor and its properties more than beneficial to health recommend it.

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