The production of extra virgin olive oil takes place mainly in an oil mill, a place designated for transforming the olives into oil, where in ancient times the stone millstones resided which today have been replaced by modern machinery capable of producing more oil in less time, while maintaining the same quality.
The production of the oil takes place in several stages: it obviously starts from the olive harvest up to the pressing. Everything in between consists of the work that millers and farms have to put in place to produce extra virgin olive oil quality.
The stages of olive oil production
The stages of olive oil production begin with the olive harvest which must be carried out in the correct period so that they have reached the right maturation and using manual and mechanical tools suitable for not ruining the drupe and therefore the quality of the oil itself. After being harvested, the olives are transported to the mill where they are weighed and recorded before being processed.
The ideal would be for the olives to be pressed immediately after harvesting to optimize their conservation. This is not always possible, therefore slotted baskets are used which allow complete aeration of the olives, protecting their quality.
The phases of their processing can basically be divided into 5 different steps:
1. washing
2. pressing
3. kneading
4. squeezing
5. storage
The washing
The olives, once they arrive at the mill and weighed before undergoing washing, are poured into a loading hopper (a sort of funnel used especially for agricultural products) whose task is to transfer all the olives to the conveyor belt which leads them to the defoliator that separates the olives from the leaves.
At this point the washing takes place, a very important phase, during which the olives are cleaned of all impurities such as mud, twigs, bark, earth.
Once washed, the olives are ready for the second phase of oil production: pressing.
The pressing
The second phase involves crushing the olives to obtain a thick and creamy paste with a pungent smell. The crushing uses mechanical discs that crush the drupes without causing friction and thus avoid heating them: in this way the activation of oxidation mechanisms (activated by heat) is avoided, keeping the quality of this paste unaltered, made up of peel, pulp and olive stone.
The pressing methods are: continuous cycle in modern mills and discontinuous cycle in traditional mills that use granite millstones that manage to crush the olives thanks to their weight. In modern mills, however, mechanical discs are used which, by rotating on the olives, allow them to be crushed and obtain a homogeneous paste quickly, thus avoiding oxidation which could deteriorate the final product.
The paste obtained is ready for the third phase: kneading.
The kneading
The paste is transferred to the kneading machine where, thanks to the presence of mechanical arms, it is mixed and gently heated; however, the temperature must never exceed 27/28°C. This phase is the most delicate of the entire oil production chain, because at this moment the oil-water emulsions break: the oil droplets are freed from the water and form larger oil droplets that float on the water itself. This breakage takes place inside watertight tanks to protect the oil from oxidation; moreover, the kneading phase must be completed in 30 minutes, otherwise there is the risk of obtaining a product with high acidity and irreparably compromised organoleptic properties.
The squeezing
The pressing is the last of the phases that lead to the production of the oil; it can be hot or cold.
In this step, all you do is separate the three components that form the paste obtained during kneading, namely:
• the oily must
• pomace
• vegetable water
The storage
Storage consists in pouring the oil into special containers that protect the green gold from light and heat sources.
For this reason, extra virgin olive oil bottles are made of dark glass, to keep the organoleptic properties of the oil itself intact.