High quality extra virgin olive oils are usually made from a blend of olive varieties in order to balance the flavour components with shelf life. Oil quantity and quality are highly dependent on the olive variety. The best oil varieties in the world have developed their reputation over centuries of production for fruit yields, oil content, flavour, keeping quality, maturity date, and ease of harvest.
Most olive cultivars range in oil content from 10 to 35 percent of their fresh weight at full maturity. Growing olive varieties with an average oil yield of less than 20 percent ~ 45 gallons of oil per fresh ton of fruit are not usually profitable to use for oil. Of the majorolive varieties grown in California, Manzanillo, Mission, Sevillano, Ascolano, and Barouni, only Mission contains a high enough oil content to plant for oil. The quality of oil made from all of these olive varieties can be excellent, but is generally regarded as inferior because they are compared to specific oilvarieties with tradition, name recognition, and marketing perception. This is similar to recognized wine varietals in the world.
Flavour components within each cultivar come from the water-soluble flavenoids, phenols, polyphenols, tocopherols, and esters that make up the bitter flavor of fresh olives. These compounds are also naturally occurring antioxidants that extend oil shelf life by reducing rancidity.The most prominent oil varieties in the world are Piqual, Empeltre, Arbequina, Frantoio,Coratina, Aglandaou, Picholine, Leccino, Chemlali, and Koroneiki. Oils with high polyphenol content have longer shelf life and are generally more bitter and pungent. I would prefer to choose a lighter flavored oil according to the the variety and harvest time, such as a late harvest Arbequina rather than buy a refined oil.
Information source amazingoliveoilOlive Oil quantity and quality are highly dependent on the olive variety,