Olive oils differ in properties and qualities. The main indicators found on olive oil labels are the levels of acidity and organic peroxide.
- Acidity: percentage of free fatty acids contained in the oil. The lower the acidity the better quality the oil.
- Peroxides: natural oxidation components found in olive oil. The lower the value of peroxide, the better the oil.
The olive is a fruit and such as any other fruit it needs cautious care. There are several factors that affect the quality and flavor of the oil:
- Fruit maturity: The amount of polyphenol and other flavour characteristics decline as the fruit matures and turns fully black. Olive oil from green olives tends to have a more bitter and pungent flavor and have a longer shelf life.
- Harvesting method: Hand picking is today still the best method to preserve the integrity of the olives and prevent bruising.
- Fruit storage: storing the olives causes oxidation, which leads to quality and flavor deterioration. Olives should be pressed maximum 48 hours after harvest.
- Transportation: To avoid compressing the olives and preserve their quality, the depth of the containers should be minimal.
- Storage material and temperature: Olive oil should be stored in a dry place, ideally in stainless steel tanks, away from light with minimum contact with air and at a temperature between 18-20C.