Virgin and Extra Virgin Olive Oil We call “Virgin” olive oil to that olive juice that has only been obtained by mechanical procedures (no refining, no added chemicals, etc…). The Extra Virgin oils are a category within the Virgin oils, being exactly the same its elaboration process. Their acidity level must not exceed 0.8º, while Virgin oils can reach 2º. We also explain in another section what acidity in olive oil is, but basically it is the parameter that allows us to differentiate between Virgin and Extra Virgin oils. Extra Virgin oils are produced with green olives, obtaining a more intense, spicy and bitter taste. Green olives have a smaller quantity of oil, a greater quantity of kilos is necessary to obtain a liter, which is the main reason for the difference in price. On the other hand, Virgin oils are obtained from ripe olives, having a milder flavor. Although technically there are nutritional differences between a Virgin and an Extra Virgin oil, they are minimal. The main differences are organoleptic (i.e., related to smell and taste).

The oil is formed inside the olive by generating “triglycerides.” Each triglyceride is made up of three fatty acids (oleic acid, linoleic acid (Omega-3) and linolenic acid (Omega-6)), which are linked by the molecule ‘glycerol’. The bond between glycerol and the three fatty acids is not very strong, so in any aggressive environment it breaks, leaving them free and the oil degrades. Acidity measures the amount of free fatty acids in the oil, which is why acidity is a general indicator of the quality of virgin olive oils. It is the percentage by weight of free oleic acid in relation to the total amount of oil. A common misconception among consumers is that acidity is related to flavour intensity. Nothing could be further from the truth: fatty acids are tasteless and cannot be detected by the palate. Furthermore, oils with lower acidity (Extra Virgin) are the most intense, spicy and bitter, while oils with higher acidity (Virgin) are milder.

Cold-extracted olive oil refers to oil that has been extracted at a temperature below 27ºC (80.6°F). The olives are crushed into a paste, which is gently heated (never exceeding 27°C) during the kneading process in mixers. This helps the oil droplets to bind together, making extraction easier.

Traditional presses are now largely obsolete in modern olive oil production, having been replaced by continuous systems and centrifuges.

Olive oil is a preservative food in which microorganisms do not proliferate. Therefore, it does not pose a health risk. However, contact with air (oxygen) and sunlight causes it to lose its properties. By law, a “best before” date of two years must be indicated, but under optimal storage conditions, it can last for several more years.

Another widespread belief is that the quality of olive oil is related to its colour. In reality, colour does not influence quality. The quality of an oil is determined by its laboratory and organoleptic parameters (smell and taste). This is why olive oil tasting glasses are blue or red — so that the colour does not affect the taster’s perception.

Several factors influence the colour of olive oil, such as the olive variety, the time of harvest, the production process, and filtration. Some producers even add chlorophyll to make the oil greener and more visually appealing. However, colour is not an indicator of quality.