How is olive oil produced, and how many categories of olive oil are there?

Olive oil is a liquid obtained from olives (the fruit of Olea europaea tree; family Oleaceae), a traditional tree crop of the Mediterranean Basin. In this blog we will introduce you to the history of olive oil, the variety of olives, how olive oil is produced, and the categories of quality of olive oils with a focus on the olive oil in Cadiz.


Olive trees were originally from the Eastern Mediterranean, Syria and Iraq areas. The Phoenicians and Greeks exported the olive trees to the rest of the Mediterranean. Olive cultivation expanded considerably with the Romans, who also improved the techniques of oil production. Olive oil from Hispania, especially in Southern Spain, was highly regarded and considered to be of superior quality throughout the Roman Empire.

The Arabs continued perfecting the technique of olive oil production.  Spaniards use olive oil for almost everything. A staple for food, skin, perfume, medicine, to preserve food, etc. Until recently olive oil was used to preserve food products and nowadays is still used to cover some cheeses to add some complexity. As a result of a stable, thousand-year-old tradition, today Spain is the major producer and exporter of olive oil in the world. Just Jaen alone, a single province in Southern Spain, produces more olive oil than the second producer in the world, Italy. Olive oil is the biggest fruit crop in the world.

Nevertheless, until a few years ago, Spanish olive oil was relatively unknown since almost all of it was sold by bulk and packaged outside the country. Today, gradually, oil producers are starting to package Olive Oil with their own names. Maybe you will start receiving more and more oil from Spain.

If you are wondering which countries produces the best olive oils in the world, the answer is Italy and Spain. Click here if you want to learn more.

Types of olives

In the world some professionals say that there are over 2000 varieties of olives. Some olive varieties are similar while others are very different. They have different looks as well as growing characteristics and preferences. Their olives vary in size, oil content, taste, chemical characteristics, ripening time, and many other factors. Here in Spain we use around 80 varieties. Just in the mountain system of Cadiz province alone you will find that they grow 20 different varieties of olives. Varieties like Lechín and Manzanilla de Zahara are varieties endemic to this mountain system.

How are olives used

Olive oil tour amount olives collected through vareo in white village Zahara de la Sierra Cadiz

To produce olive oil the olives have to be picked up from the tree first. There are two ways to pick them up, manually or with machinery.

If you use machinery to pick them up the machine will grab the tree and shake it to force the olives to fall to either the umbrella that the machine holds or to the net that people would have set up beforehand.

Olive oil tour vareo tourists in white village Zahara de la Sierra Cadiz

If you are picking the olives manually, traditionally, the olive pickers have to set up the net under the olive and then with a stick will hit the branches like if they were brushing the branch to force the olives to fall but to prevent harming the tree.


Table olives:types of Table olives in food market Cadiz Explore la Tierra

Olives are not tasty if taken and eaten straight from the tree. To be able to eat them  you have to leave it in water and change the water several times. After that you can process them and marinate them. The type of marinating is dependent on the variety of olive.

Olive Oil

To produce olive oil they will take the olives to an olive mill. Here they will put the the olives in a machine which will do the whole process. They must take the olives as soon as possible and not from the ground, as olives start fermenting very quickly, around 6 hours after falling from the tree.

Olive oil tour Olive oil mill in white village Zahara de la Sierra CadizFirst part of the process consists of taking the leaves and branches off and washing the olives. Farmers mix these leaves and branches with animal feed to feed their cattle. The olives head to a centrifugal machine which will take the oil juice apart from the pip and the skin. Industrially, to extract the olive oil the mills centrifugate and do not press anymore. The skin produces “orujo”, a low quality oil. The pips are used to exfoliate the skin in creams. Pips and skin can also produce energy.

Once we have the olive juice we pass the liquid through a machine which will keep the oil at less than 28ºC. This helps to extract less oil but with better quality (labelled as cold-extracted).

This oil juice passes through a centrifugal machine which runs at ~4500rpm to separate the olive oil from the water. Then the oil is left to set and the solids and water to lay at the bottom. When the bottom of the container opens only the water and solids leave the container.

The oil is then kept in a sealed container where no air, light or temperature variation will affect the quality of the olive oil.

Only around a 16% of the mass of the olive from the beginning will actually become olive oil.

Categories of Olive oilOlive oil tour tasting in white village Zahara de la Sierra Cadiz

To differentiate the different categories of olive oil, the experts have to look at the whole process, the aromas and characteristics of the olives without noticeable defects, and the acidity.

Extra Virgin Olive Oil

This is the best quality of oil. Of all the olive oil produced in Andalusia, only 20% enters within this category. It is produced with only physical and mechanical processes and full of aromas without any defects.

Virgin Olive Oil

If the extra virgin olive oil spends too much time in the bottle or in the industry, the aromas and characteristics are not the same. As well, if the acidity of extra virgin olive oil does not surpass a certain amount then the quality of the olive oil goes down becoming Virgin olive oil. To enter this category the olive oil produced must come from only physical and mechanical processes.

Olive Oil

Second centrifugation enters this category as the olive oil produced is poorer quality. Older unsold bottled oil is also sent back to the factory and mixed with better quality oil and other chemicals to improve the acidity to enter this quality.


If you would like more information on visiting olive oil production or gastronomy and wine tours let us know. We can provide a guide which will help you enjoy the region to its fullest and help immerse yourself in the local culture.

Sherry tours

Are you visiting Cadiz and you would like to learn more about Sherry and immerse yourself in the local culture and traditions by doing a Tabanco tour in Jerez de la Frontera? If you want to learn and experience it with the company of a local guide and turn your visit to Jerez into an exciting gastronomic adventure, book with us. Sherry love is very contagious, surely you will also become a Jerez lover!

If you have your own transport you can book a tour guide who will go with you for a day or half a day and enjoy learning about Sherry and enjoy the best Sherry bodega tours, local culture and traditions and the local gastronomy. In case you do not have a transport we can arrange transport, restaurant and the rest of your trip for you.

If you would like to learn all about Jerez-Sherry-Xeres D.O. and let us arrange the visit to the bodegas and the rest of the trip for you, then join us for our Ultimate Sherry Tasting tour. We can design a private tour just for you and your family.

If you would prefer, we can organize a private wine tasting event at your rental place/apartment. We will go to your place and do a Sherry tasting for you privately, from basic Sherries, premium Sherries or VORS and premium Sherries.

If you are thinking to travel to other parts of Cadiz, we are based in Vejer de la Frontera. Officially, Vejer is one of the most beautiful villages of Spain, you should come and meet us!

Food and cultural tours

We do small Sherry & Tapas tour in Vejer where you will taste different types of Sherry and local food like bluefin tuna, bull meat, salmorejo, eggplant with honey and pinenuts, etc.

We also have a tour that focuses on Bluefin tuna. You will learn the history of Bluefin tuna in the area since Phoenician times; visit an Almadraba, visit a local food market; and taste different parts of bluefin tuna in all ways, salt-dried, grilled, raw…

If you would like to visit other beautiful white villages like Vejer, we can do a tour of the white villages in Cadiz province. On the other hand we can mix a visit to a beautiful white village wit a visit to an olive oil mill. Or you can choose to do a private tour that we can design especially for you based on your interests. Come and join Explore la Tierra in Vejer de la Frontera, Cadiz, Spain!

Contact us

To learn more about sherry, culture and travel guides, please hit the big blue button to read other blog posts. If you have any ideas and suggestions, please do not hesitate to write us an email at info@explorelatierra.com. Please read our privacy policy before you get in touch with us. We will take your new recommendations into consideration.

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