It is not uncommon to see olive oil labels that boast the terms “cold pressed”, “first press” or “first cold press”. It sounds wonderful and evokes a romantic image of an old wooden press with beautiful golden oil flowing out. But what does it really mean? Could it be just another marketing gimmick? To understand if these terms have meaning today, we need to look at where they came from. Let’s go back in time to the old-fashioned way of making olive oil.
Fifty years ago, most oil was made in vertical presses: the olive paste was spread on mats (imagine a very tall paste sandwich) and pressed to make “first cold press” olive oil. The paste was then mixed with hot water or steam and pressed again to remove more oil. This "second pressing" was not as good; the heat had evaporated some of the delicate flavors and healthy components.
Today, the vast majority of extra virgin olive oil is made in centrifuges in a single, continuous process. As for oils still made from presses, they are generally inferior quality for a few basic reasons. Because the mats are difficult to clean, the press can produce chemicals responsible for winey and fusty defects. Additionally, the open environment of the press and the time consuming process creates more exposure to oxygen, resulting in more oxidation and a higher level of peroxides. The antioxidant content is lower than in oils made with centrifuges, so the oil is not as healthy and the shelf life is shorter. If anything, the term “first press” on a label should be a warning signal, rather than a sign of quality.
Even with the use of modern equipment, however, it is true that the paste may still be warmed up or heated up. It can be warmed up or heated to a moderate degree without significant oil quality degradation. Olives are often harvested in the winter when it is cold, and the paste may be warmed to room temperature during the malaxation process to make it easier to work with. According to the International Olive Oil Council regulations, this is still considered "cold extraction" if the paste is kept under 27ºC (80.6ºF). Heating the paste beyond this level increases yield, but degrades the flavor of the oil and can result in the oil not qualifying as extra virgin if the heat is excessive. After the oil is extracted from the paste, the dry pomace (pits and flesh) is sometimes sold to refineries where steam and solvents are used to remove any residual oil. This oil is called olive-pomace oil.
So “first cold press” is most often marketing language that may not reveal anything about oil quality or the process under which the oil was made. “Cold extraction” really means “extraction at not too high a temperature.” If you want to buy a high quality extra virgin olive oil, it is best not to rely on romantic language on the label. A safer method is to rely on the COOC seal of certification or the upcoming USDA certification.