Origin
Origin alone is not a guarantee of quality, because olive oil is good when it’s made well, and regardless of where olives are grown they can have qualities and defects, like all produce.
During the ripening phase, called veraison, olives change colour several times: from green to yellow, to reddish, to purple, to brown, to black. Each variety has an optimal degree of maturation; extraction during this stage best enhances the oil’s sensory characteristics and achieves the best fragrance and flavour.
Like wine and other natural products, from year to year olive oil is the result of a number of factors that can affect its characteristics.
An example is the amount of rain that the trees may be exposed to during the season, which can cause significant variations in the bitterness of the product.
Qualitative classification
In this regard, it is not uncommon to hear terms such as “first cold pressing” or “cold extraction” of olive oil – two denominations allowed by law that consumers associate to a specific quality meaning.
Actually, “first cold pressing” refers to oils obtained by a traditional “pressure” extraction system, where olive oil comes from the first pressing. It is actually obsolete, as olives no longer undergo two extractions. Moreover, a traditional pressure extraction system today yields oil that is, at best, mediocre: the best quality oils are obtained from modern centrifugation systems.
In any case, “cold extraction” only guarantees that the temperature did not go above 27ºC during the process. This is definitely not enough to obtain a quality product, since the pressing of defective olives will still yield a poor quality oil.
The cloudiness of olive oil
Another misconception to debunk is that the cloudiness of olive oil is an indication of quality. Oil can appear cloudy because it contains a significant amount of vegetable water and olive pulp pieces. The presence of water and olive pieces causes faster deterioration of the oil’s organoleptic and nutritional properties. The filtering process of extra-virgin oils enhances and keeps intact all the beneficial properties of the product, so that it can be preserved better and for longer.