The olive tree varieties that still exist come from the cultivation made 6000 years ago in the siro-palestinean area, where the oldest testimonies were found.In fact, the cultivation of olive trees, as well as the vines , corresponds with the evolution of human beings in the whole Mediterranean area.Italy, especially, remains the biggest producer of high quality olive oil and Tuscany plays an important role in this.The olive harvest is done between November and March depending on the different olive tree varieties and the different regions. Tuscany is one of the earliest Italian regions to harvest.Olives are picked by hand before they are fully ripe. Whilst this obtains less quantity, it ensures a higher quality, verifiable in the particular peppery taste and the green colour obtained.As soon as the olives have been picked and collected in small boxes, they must be taken very quickly to the olive mill where the process of oil-making will start straight away.This process consists of three main stages and it is interesting to notice that the first two steps have remained almost the same since olive oil was first produced, with the only change being in the kind of machinery employed .After the olives are separated from their leaves and washed, firstly they are crushed and secondly the resulting dough must be thoroughly amalgamated.The third important step, which in recent times has had various evolutions, consists of separating the water from the olive oil. In the past this was done with a presser machine, nowadays more sophisticated systems allow it to be done by calculating the physical laws (the different specific weight of oil and water).At this point the new olive oil is ready to be bottled, although it is usually filtered to avoid possible residues in the bottle.The high quality of the olives is the most important factor to obtain a high quality oil.For an olive oil to be defined as extra virgin, it must have an acidity level of not more than 1 gr. per 100 gr. Chemical analysis testifies this before the oil can be bottled.Unlike wine, the younger the oil, the better it is and it is advised not to buy it after it is 18 months old, and even after the first year it will loose a bit of its better characteristics, as well as its colour, which will turn a deeper yellow (this is particularly visible in the extra virgin Tuscan oils).Modern scientific researches have confirmed the healthy virtues of olive oil in the alimentation, especially comparing the lower risks of cardiopathic illness in the Mediterranean countries, in comparison to places where butter and other kind of fat produces are used instead of oil.