PRODUCTION OF OLIVE OIL IN PORTUGAL
An annual production of approximately 90,000 tons of olive oil makes Portugal the eighth largest producer of olive oil in Europe, constituting some 2% of total European production.
The ranking becomes slightly different, however, when one considers the figure of consumption per inhabitant. Here the Portuguese take their place at fourth in the world, with some 5 litres per person annually. By way of comparison, the Germans consume 0.8 litres per person annually. World champions in this regard are the Greeks, who contentedly consume 20 litres per person each year.
The various soils and the differences in climate found in Portugal serve to determine which variety of olive trees are planted, and so provide a basis for the great variety of Portuguese olive oils.
The olive harvest takes place – according to the ripeness of the individual varieties – between September and February. Achieving optimum ripeness is of the uttermost importance for the production of a high quality olive oil.
If the olives are ripe, they can be harvested in three different fashions:
- olives are picked by hand
- olives are beaten from the branches with sticks and collected in a net or a cloth
- ripe olives, fallen from the tree, are collected from the ground.
After harvesting the olives must be brought to the oil mill immediately for processing. After being cleaned, the olives are chopped in a grinder made from stone or metal, seeds included. From this comes a pasty mass, a sort of a must that is then put into another machine for agitation, so that the drops of oil collect together and can be extracted. Finally the paste is placed under vacuum in a centrifuge, where the water content can be separated from the fruit juice, the oil. Subsequently the last drops of water are removed in another centrifuge – the entire process takes some 30–40 minutes.
The interval between harvest and processing should ideally be as short as possible. The optimum elapsed time would be less than four hours, although an interval of ten hours is considered acceptable. But not only efficient use of time is important; the processing temperature also plays a significant role. Thus virgin and extra virgin olive oils can only be cold-pressed, which demands that the temperature during the procedure can never exceed 27°C.
If the solids suspended in the freshly pressed oil are not filtered out, one obtains ‘unfiltered’ or ‘naturally cloudy’ olive oil, which will remain fresh for a few weeks, but quickly diminishes in quality. When the solid particles are filtered out of a freshly pressed olive oil, the oil will maintain its quality for a longer period of time.
The fruit water removed during processing is immediately collected, to ultimately be used as fertiliser in the olive groves, since it contains valuable minerals and vitamins.