Olivicoltori Toscani Associati

Varieties

The olive tree is a typical element of Tuscan landscape. On Tuscan hills, covered with olive trees, many different olive trees can be found, which will give a heterogeneous product. Oil is one of the few product, which is made only from the fruit, without anything added to it. For this reason, different olive varieties will give a heterogeneous product. Here are the most common olive varieties in Tuscany:

	Frantoio variety Widespread in all Italy, it has a high and constant productivity and give a delicate and aromatic taste to the oil.
	Moraiolo variety Highly diffused in Tuscany as well as in Italy and in other countries of the Mediterranean area. It has a high productivity and it is very resistant to wind.
	Leccino variety Cultivated in Tuscany as well as in other areas of the world, it is very resistant to bad weather conditions and to some diseases. Its productivity is high and constant.
	Pendolino variety This variety comes from the area around Florence and it is cultivated all around Tuscany. It has been highly diffused for pollination. The fruit ripens quite early and has a constant and high productivity.

The picking

The picking of the olives by hand is still the most used method: small rakes made of plastic, ladders and nets era used in order to separate the fruits from the tree. In the last few years machines have appeared on the market (vibrating machines), which help to harvest more quickly without damaging the fruit.
The olives are then the stored for a short period and then brought to the oil mill in perforated baskets, for the air to pass through, in order to prevent them from getting rotten. Before the pressing the olives are washed with water
Then they are crushed, in order to obtain a homogeneous paste; this can be made with grindstones, hammers or disks. The paste undergoes a process of continuous stirring, in order to let the small drops of oil unite form bigger drops, to make the extraction of the oil easier. This stage of the pressing is called “gramolatura” (kneading) and usually lasts from thirty to forty minutes.
The characteristic of the oil is that it is one of the few alimentary products, whose quality depends on the freshness of the olives, on their ripening stage and on the technological operations made to obtain

The pressing

The olives can be pressed with two different methods:
- traditional method (discontinuous method)
- the continuous method

Discontinuous method: it is the old used to press the olives and still nowadays grindstones made of granite and hydraulic presses are used. The grindstones break the pulp and the pit of the olives and continuously mix the paste, too, kneading it in order the smaller drops unite to form bigger ones, which make it easier to extract oil.
Continuous method: it is a modern method to press the olive. The pressing machines can be conical, disks or hammer, which work very quickly but warm up the past and the another machine to mix the paste is needed. During the phase of kneading of the paste, this reaches a temperature between 28 and 30°C.

Extraction of the oil
Discontinuous method: once the paste has been obtained, it is put on disks made of vegetable or synthetic fibre, called “fiscoli”, forming a layer of about two-three centimetres. A steel disk is put every three “fiscoli” and then they are piled around a cylinder, with a perforated surface.
The cylinder is in vertical position on a steel vat. The piled disks are then put under a hydraulic press, which exerts a pressure of more than 400 atm. Then a separator or the decantation method will be used in order to separate the water from the oil.
Continuous method: a decanter has to be used. This can have two or three phases. The decanter is a centrifugal separator; it consists in a cylinder made of steel, inside which there is another cylinder, which ends in a cone. A spiral is inside this cylinder. All the parts, which form the centrifugal separator, are made rotate by an engine. A two-phase is the one, which separates the solid part from the liquid one (the oil and the water). A three phase decanter instead, separates also the water from the oil. The extraction of oil is made possible by the centrifugal force, which works according the physical principle of the separation of substances, which have different specific weights. The separator machines will then clear the oil.
Various researches have found some slight differences in oil produced with these two different methods. The traditional one can imply risks for what hygiene is concerned; in fact, using the grindstones a bigger part of the olive paste is exposed to the air, which causes the oxidation of the oil and affects its preservation. With the continuous method, since warm has to be used, there is the risk of warming up the oil too much. Anyway, this doesn’t usually happen.

Storage of the oil

Oil is a very perishable product; its characteristics can be altered by light, air, low temperatures, which cause freezing, and high temperatures, which alter its biochemical characteristics. Since ancient times the oil was kept in jars and amphorae made of terracotta, which are nowadays glazed inside with particular glazes, made according the new hygienic rules. Anyway the stainless steel containers are now more common.
It is very important that the container used for the storing of the oil is very easy to clean and that it prevent air and light to damage the oil. The oil has to be kept in a place, with a temperature no higher than 14-15°C and no lower than 3-4°C, in order to prevent chemical alterations of the product. It would be better to take it home in small quantities, and leave the rest in a storing room with the right temperature and the right light conditions.

Every stage of the production of oil is very important to determinate the quality of an extra virgin olive oil. If the fruit is damaged, for example, or it has been attacked by parasites, or it hasn’t been stored in the right way, the quality of the final product can be severely affected.

Classification

PIn order to control the quality of the product obtained, a lot of chemical analyses are made, among which the ones to check the acidity level and the number of peroxides, and the organoleptic analysis colled “Panel Test”.
From the results of these analises the oil categories are classified according to Eu regulations.
The consumer can buy:

- Extra virgin olive oil: it is made from the fruits through a mechanical process and is the best quality one.
- Virgin olive oil: it is made with the same process as the extra virgin, but is of lower quality than the extra virgin.
- Olive oil-a mix of refined and virgin olive oil: it is made from a blending of different olive oil varieties, refined with virgin olive oil.
- Olive residues olive oil: it is made from a blending of oil made from olive residues, refined with virgin olive oil.