Single Varietal Extra Virgin Olive Oils are those produced only with a specific variety of olives.
Most of the olive oil produced in Spain is elaborated by cooperatives. Cooperatives are groups of farmers in a town or county, who agree to construct a mill for grinding their olives and then sell the oil with the cooperative brand.
Commonly, olive farmers have different varieties of olive trees. For years, and even nowadays, farmers after a harvesting day carry their olives fruits to the mill, where those also harvested by other farmers are mixed and milled together. The result is an olive oil composed by several varieties.
In the last years, with the construction of mills in private farms, where olives are controlled and separated by varieties, monovarietal extra virgin olive oils are being produced, and consumers are learning to identify the characteristics of each one. Therefore, many cooperatives have changed their procedures, organizing to the farmers to identify the varieties, mill them separately and produce single varietal olive oils.
The following tendency is the realization of coupage or assemblies of single varietal olive oils, which are mixtures duly controlled in different percentages to obtain new aromas and flavors, trying to improve the characteristics of a healthy variety with the addition of a certain percentage of another, for example, with more quantity of antioxidants.
Actually the variety does not affect the quality of the olive oil. You can produce varietal olive oils that can be extra virgin or lower qualities olive oils, according to the way in which the olive is milled.
Another subject are the tastes, it is possible to produce extra virgin olive oils (EVOO) of different varieties. Some consumers prefer the oils a bit bitter, typical in the mixture of different varieties of olives, while others do not like it at all. The fruity notes are different among varieties, which are only distinguishable in extra virgin olive oils. Some varieties have notes of tomato, other of almond, artichoke, bananas, etc.