The stages of olive processing

What are the stages of olive oil production?

Are you curious to learn how olive oil is made at Il Frantoio Il Mandorlo? Let’s take a look at all the stages of olive processing together, to see what happens after harvesting and before bottling in the hills of Florence.

Washing and defoliation

Washing and defoliation are the first two stages of the processing and are essential for obtaining a quality product, for its safety and for the correct operation of our machinery.

The olives are unloaded into one of the three external hoppers with a capacity of 40q each and are sent on a conveyor belt to the defoliator. Once the excess leaves and any coarse branches have been removed, they are washed to eliminate any residues of plant protection and/or pest control products inside a cycled motor. Finally, they are dried through a steel vibrating screen.

Crushing

In our plant we use one of the most modern crushers in circulation today: the toothed disc crusher. This particular crusher rotates at a variable speed between 1400 and 1600 revolutions per minute, which is necessary to break the vacuoles of the mesocarp cells of the drupe, inside which the major component of the oil is located.  

Compared to other crushers, this type of rotation makes it possible to avoid excessive overheating of the olive paste and a significant amount of water-oil emulsions, facilitating the malaxation process.

Malaxation

Malaxation is one of the most delicate phases of the entire olive processing process, where the olive-oil maker’s hand leaves its mark. From the technical point of view, this phase is indispensable for breaking the water-oil emulsions and for the coalescence process of the oil microparticles, that is to say the gathering of small droplets in a continuous oily phase. In our plant we have six semi-cylindrical malaxers of 4q each

Based on the studies carried out by our father Luciano, in 2017 these were equipped with semi-cylindrical covers with the aim of reducing the air flow between the paste and the cover of the malaxers themselves, limiting the activity of the polyphenol oxidases, which are enzymes responsible for the oxidation of oil. The malaxation times for obtaining an excellent final product, according to our philosophy, range between 30 and 45 minutes with temperatures varying between 24 and 27°C.

First separation (Decanter)

In one of the last processing stages, the olive paste is separated by means of a decanter, horizontal centrifuge, in three phases for the difference in specific weight: olive pomace, then given to a biogas plant after having extracted the kernels that are put on the market and used as fuel for boilers and stoves, vegetable waters used as agricultural fertiliser and oily must.

Final separation

In the last stage of the entire process, the oily must is transferred to vertical centrifugal separating machines, which eliminate the last residual solid and liquid microparticles, agents of the oil’s foundation.

Filtering

Lastly the oil is filtered through a specific machine equipped with a pump, a perforated steel drum and bags of non-woven fabric that give the oil a brilliant appearance, extending the conservation times of the quality and nutraceutical properties of the oil we produce.

Do you want to crush your olives and follow the production of your oil step by step?