EVOO: Acronym for 'extra virgin olive oil,' the highest classification of olive oil, representing a product free of defects, full of flavor, and devoid of any chemical processing.
Acidity: Acidity is a measure of the quality and freshness of the oil. Extra virgin olive oil is required to have acidity less than 0.8%. The acidity test measures the oleic acid in the oil. Virgin olive oil (lower classification) has an acidity range of .9 to 2.0%.
Peroxide Index: A measure of the amount of active oxygen, or oxidation, in the olive oil. The amount is shown in the equation: meq 02/kg, i.e. milliliter equivalents of oxygen per kilogram of oil. The higher the oxidation of the oil, the higher the peroxide index. Higher peroxides can lead to olive oil becoming rancid faster. Als, when a bottle of extra virgin olive oil is exposed to the light it increases the peroxide value, leading it to deteriorate faster. EVOO Storage Tip: keep your olive oil away from the light!
Extra virgin olive oil is required to be below 20 meq 02/kg and high quality extra virgin olive oils need to be below 10 meq 02/kg.
Early Harvest EVOO: The olives are picked early in the season and consequently have less acidity and more polyphenols. Early harvest practices produce higher quality olive oils with a fresher taste. Some can have a slight bitterness, which is due to the higher plyphenols and antioxidants. These olive oils are more costly to produce, resulting in higher prices.