Production Steps

vovabolario sensoriale

The quality of a product depends on the raw material but also on how it is processed. In fact, to obtain a quality extra virgin olive oil, the production method is fundamental. In Italy, 53% of the olive tree is widespread in the hills, 44% in the plains and 2% in the mountains. For optimal growth, the olive tree needs a mild climate. Precisely for this reason, cultivation is more widespread in the SOUTH (77.9%) and CENTER (19%) regions, while in the north, cultivation is more limited (2%).

The olive tree is a very long-lived evergreen plant, it can live hundreds of years. To bloom, this plant needs a temperature below 7 ° C for 2/3 months a year. The first small flowers are called little fingers, and the little finger starts between March and April. The actual flowering instead varies according to the areas from May to the first half of June. Harvesting usually takes place from mid-October until the end of December.

Harvest

The olives are harvested with different methods according to the techniques adopted by the farmers; for example:

The branches of the plants are beaten with flexible sticks in order to cause the detachment of the fruits.

Expect the complete ripening of the fruits and their spontaneous fall from the plant.

Use of mechanical pickers which by shaking the branches allow the olives to fall to the ground.

Handpicked with combs and shoulder bags on very long ladders.

Raccolta olive
Raccolta e stoccaggio olive

Olives preparation

The olives are weighed and then stored in thin layers inside perforated boxes which improve ventilation and avoid fermentation.
The environment must be fresh and sufficiently ventilated and the storage time must not exceed 24 hours.

Before moving on to the actual extraction, the olives are subjected to a thorough cleaning in order to avoid any hygienic risk during the production processes. The olives are poured into a hopper and from there into a defoliator that sucks up the leaves and any remaining twigs.

Once defoliated, the olives pass into a sort of washing machine that removes any residual earth, dust or surface pesticides that would compromise the quality of the oil. Washing is carried out with running drinking water.

Milling and pressing

Milling is the first phase of actual extraction, here the cellular structure and the membranes of the olives are broken by mechanical means.
In this phase the oil paste is obtained, a semifluid compound consisting of a solid fraction (consisting of kernels, peels and pulp) and a liquid (an emulsion of water and oil).

The systems used are:

Classic milling
: it is carried out by means of the mill, a traditional tool derived from the ancient stone millstones. The olives undergo a mechanical action through the rotation movement of the stone wheels which result in the fragmentation of the kernels with the rubbing of the sharp edges and the escape of the juices.
The processing with the mill is done by a very slow rotation.

Hammer crusher: it is preferred to classic milling as it integrates perfectly with modern continuous cycle extraction systems.
The hammer crusher has a series of rotating discs equipped with edges that rotate very quickly (from 1500 to 3000 rpm). In this case the impacting action of the stone edges has a marginal role; The breaking of the pulp occurs mainly due to the impacts of the rotating devices. This method is suitable for continuous cycle production, with automated loading and unloading procedures.
Image
Molitura e frangitura olive

kneading

This phase follows the milling (or pressing) and is used to break the emulsion of water and oil and to bring together the small oil micelles present.

The machines used are called kneaders or kneaders; they are made up of a steel tank with helical blades that rotate slowly keeping the oil paste in continuous mixing.

They are often used in series where the oil paste passes from the first to the last, to allow a better processing.
Gramolatura olive
Estrazione Olio di oliva

Extraction

With this operation, the liquid part (oil and water) is separated from the solid part (the pomace: formed by fragments of stone, peel and pulp). There are several extraction methods that make substantial differences in product quality:

Extraction by pressure
: the oil must is filtered by using a pressure, thus separating it from the pomace. The pressure is carried out inside a hydraulic press. With this type of extraction excellent quality pomace is obtained.
Centrifugation extraction: it is the most common method in which the oil paste is subjected to centrifugation at a speed of 3000-3500 rpm. Centrifugation takes place in a decanter.
Percolation: this method exploits the difference in surface tension of the vegetation water and the oil, making the oil more easily adhere to a metal surface than the water, which is separated by percolation. The oil pasta is contained in a tub; it is made up of a series of steel blades that lift and scrape the oil from the walls of the tank, making them flow into a collection system. This allows to obtain a very high quality oil.

Separation and Storage

SEPARATION

With the extraction methods described, excluding percolation, the oil obtained always contains residual water that must be removed.

In this regard, the methods used are Decanting and Centrifugation.

Decanting is a method based on the non-miscibility of oil and water. The oil is lighter than water and at rest it surfaces on the surface, separating from the water. However, the product obtained in this way does not have an optimal yield.

Centrifugation (vertical) is used to separate the oil from the water, both on the oil must and on the vegetation water.

STORAGE

At this point the product obtained is ready for consumption but contains solid residues and is cloudy at sight. For this reason, if it is not to be marketed immediately, it is stored in steel vessels in an atmosphere containing nitrogen (to prevent oxidation) so that solid residues settle spontaneously.

If, on the other hand, the oil is immediately destined for marketing, it will be filtered before being packaged.
Separazione e Filtraggio olio
Stoccaggio Olio