Extra virgin is the highest quality and most expensive olive oil classification. It should have no defects and a flavor of fresh olives. In chemical terms extra virgin olive oil is described as having a free acidity, expressed as oleic acid, of not more than 0.8 grams per 100 grams and a peroxide value of less than 20 mill equivalent 02.
It must be produced entirely by mechanical means without the use of any solvents, and under temperatures that will not degrade the oil (less than 86°F, 30°C).
Since extra virgin olive oil is simply pressed fruit juice with out additives, the factor influencing its quality and taste include the varieties of olive used, the terroir (the environmental conditions, especially soil and climate, in which the olive trees are grown and that gives the olive oil the unique flavor and aroma), and the countless decisions, production practices and the dedication of the producer.
In Greece there are several varieties of olive trees. Among others, the most popular and most common are Manaki, Koroneiki, Ladolia, Athinolia (Tsounati) etc.
During the stages of maturity, olive fruit changes color from green to violet and then black.
Olive Oil taste characteristics depend on which stage of ripeness olive fruits are been collected. Olive Oil coming from green to violet olive fruits contains large amounts of phenolic and aromatic compounds and has intensive fruity and herbal taste (Koroneiki and Athinolia variety).
On the other hand, as the fruit becomes ripe the amounts of phenolic and aromatic compounds are getting lower. The taste of olive oil that comes from violet to black fruits is softer and its aroma reminds ripe fruits like apple, tomatoes and sometimes Almonds (Ladolia and Manaki variety).
This is the most popular variety in Greece. The 60% of the total Greek production is Koroneiki, it has a small size and matures relatively from October to December, its weight from 0.3 to 1.0 grams and its length from 12 to 15 millimeters.
Although the fact that Koroneiki tree needs minor attention and can stand low temperatures during the winter, it gives the finest olive oil comparing to other varieties.