Olive trees are mythical trees and symbols of immortality. They are part of the identity that merges with the history, tradition and culture of the Mediterranean people. Its origin dates back to the tertiary period, in Asia Minor – perhaps Syria or Palestine – where traces of oil production and pot fragments dating back to the early Bronze Age have been found. However, fieldwork across the Mediterranean has identified fossilized olive leaves dating from the Paleolithic and Neolithic. In Egypt 6000 BC, the merit of the cultivation of the olive tree was attributed to Isis, wife of Osiris. Around 3000 BC, the tree was already cultivated throughout the “Fertile Crescent”, whose spread of the tree throughout Mediterranean Europe was due to the Greek civilization. Its name comes from the Latin oliva, which in turn comes from the Greek λαία (elea). From Mycenaean Greek e-ra-wa (elaiva) or oil … “Olive oil” from the Arabic word “Az-zaite” which means olive juice.

Olive oil has always played a very important role in human history, from cooking to health as a medicine, in relieving pain and treating wounds., perfume, as well as fuel for lighting, lubricating oil for tools and even to make fabrics waterproof. Later, olive grove cultivation spread throughout the Mediterranean and, with Portuguese and Spanish maritime expeditions, the olive tree crossed the ocean towards America. It spread throughout the world: Argentina, Australia, Chile, the United States of America, to Japan, Mexico, China and South Africa, among others. For example, in Portugal, olive oil emerged as a commercial exchange in 1266 in the Community of Silves. The only geographical limit to their proliferation was the cold climate, as olive trees hardly withstand temperatures below 12 degrees Celsius. On the other hand, it withstands considerable droughts and strong winds. Throughout history, the olive tree has always been present in the daily lives of societies due to its characteristics of resistance to all types of soil and weather. It has been associated with religious practices, myths and traditions, artistic and cultural manifestations or even medicine and gastronomy. The olive tree is a symbol of wisdom, peace, abundance and triumph. Currently, it is possible to find unique specimens in Lebanon and Italy7.

– From Olive Picking to Olive Oil Manufacturing –

Every year the olive trees bloom during the winter, that is when chemical fertilizers are used to control pests, but production is totally dependent on natural factors. However, the Galician olive tree, which is indicated for the production of olive oil, does not require special care. The big secret is to keep the land clean and to be pruned, this will be enough for thirty to forty medium-sized trees to produce enough for family consumption. A harvest of around 400 to 500kg can be expected, from which it will be possible to obtain around 40 to 50 liters of oil. From its flower the fruit is born, which from October will be ready to be picked and picked, when it is black and ripe.

At the right time for picking the olives, spread blankets, cloths or fine nets under the olive tree and tap the branches with a stick in order to cause the olive to fall. After harvesting and gathering, the olives must be cleaned, separated from the leaves and pieces of vine. It should only be bagged when it is very clean. After cleaning, it must be stored properly, allowing it to keep its characteristics unaltered, for a period of time that is not too long, at most, one to two weeks. Due to its enzymatic constitution its lifespan is relatively short. At the mill, it starts out being heavy. For each kilo, the mill charges the milling. Then, it enters the transformation process, the bags are poured into a funnel-shaped tub, subsequently washed, and taken to the mill, it leaves in paste and enters a kneader that moves it and adds a little hot water while it waits for entry into the centrifuge. In this machine, whose operation is similar to a washing machine, in the twisting process, with a very high rotation speed, thus extracting all the liquid.

To obtain an excellent product, some very important procedures must be taken into account, namely, when it is harvested, the olives must be picked and cleaned as soon as possible, preferably at the end of each day, as the olives too long mixed with the leaf, it starts to heat up and ferments, eventually rotting, or changing the flavour and raising the degree of acidity. It must then be stored in plastic bags for this purpose.

The bagasse, the solid part that remains, is expelled to the outside. The liquid obtained (olive juice) is now conducted to another machine, which will separate the oil. It is in this new machine that the spin principle facilitates the entire process. In this new phase, some hot water is added (about 40º degrees). When the temperature is too high, it scalds the oil too much, depriving it of its properties. After several days of hard work, we will have pure oil of excellent quality, with an acidity of 0.6º.

In fact, the manufacture of oil consists of crushing the olives to obtain their juice. In traditional presses, this process was done by pressing, leaving it to rest for some time in the bins (deposits) being the lighter oil, by the decanting process, it began to join the surface, and underneath the remaining liquid. There are oils of various characteristics, depending on the variety of olives and region, and the oil from Galician olives proves to be a balanced product, smooth on the palate with a fruity aroma with low acidity. Depending on taste and use, a good oil can go from two tenths of acidity to two degrees, with a fine oil being more beneficial to health. Acidity is defined as the percentage of existing oleic acid,

The journey of olives and oil reveals a line that runs through the Algarve mountains and ends at the sea. This trail covers the families that perpetuate the activity, the means that produce this sacred oil, the businesses that derive from the fruit of the land… even the traditional sweets and liqueurs, the restaurants and their dishes bathed in the flavor that so much narrative originates, day after day.

Oteros, Jose. (2014). Modeling of the olive reproductive phenological cycle (Thesis Doctoral). Universidad de Córdoba, Córdoba, Spain

The Olive World: https://en.loa.pt/a-historia