About Olive Trees
Olive trees thrive in warm dry climates. They are drought tolerant and do not require rich fertile soil. Their root zones tend to be shallow so they adapt well to drip irrigation. Their blooming cycle is triggered by the rising soil temperature in early Spring. And, the liquid in the olive does not change to oil until the night time air temperature starts to drop below 55 degrees in the fall.
Olive trees are self-pollinating. They do not use bees or insects to pollinate. The blooms on an olive tree are very delicate and can be damaged by high winds, heavy rain, or hail. Thus, spring storms can greatly impact the olive fruit load or yield. The California Central Coast’s warm spring days and gentle afternoon breezes are perfect for pollinating olive trees.
The olives used for making olive oil tend to be smaller in size than the olives used for table olives. The smaller olive size can also be attributed to what is called irrigation deficit. Research has found that by restricting the irrigation to an olive tree by 10 to 15 percent, during the summer months, creates better tasting olive oil. This practice would be detrimental to the development of larger olives used for table olives. Also, the irrigation is restricted for a couple of weeks prior to milling the olives for olive oil to lower the water content.
Olives are harvested by hand or for some varietals like Arbequina, Arbosana, and Koroneiki can be mechanically harvested. Once the olive is removed from the tree it starts to decompose and if the olive is bruised during harvesting the bruised area decompose even faster. Thus, for the best tasting olive oil, olive farmers try their best to minimize damage to the olives and rush their olives to the mill as fast as possible. Fruit fly damage to the olives can also negatively impact olive oil flavor. A Mediterranean olive fruit fly found its way to California in the late 90’s. Fortunately, the California Central Coast region tends to be hotter and dryer than the typical Mediterranean climate so the olive fruit fly is generally not as much of a problem here as it is in the Mediterranean. Proper pruning of the olive trees and the use of fly traps also helps to manage the fruit flies.
Typical olive tree cultivars used to make olive oil grown in the Central Coast region of California
(Listed by country of origin)
Koroneiki – The most common variety grown world wide for olive oil production. Robust flavor with pleasant peppery finish.
Coratina – From the Southern part of Italy. The olive oil is bold and flavorful. Producers try to balance fruity, bitterness, and pungency.
Frantoio – Primarily found in Tuscany, this olive oil is very flavorful
Leccino – This olive oil is rich and buttery if the olives are allowed to ripen. If more green olives, then the oil tends to be more pungent.
Maurino – Fruity and flavorful with a peppery finish.
Moraiolo – Another Tuscan varietal that is very fruity and flavorful.
Pendolino – Pendolino is an excellent pollinator so it is typically planted along with other varietals in the orchard. The olive oil is typically used for blending with other Italian varietals.
Taggiasca – From the Genoa area of Italy. Taggiasca is a very flavorful fruity olive oil. Typically blended with Leccino and Pendolino oils.
Arbequina – Commonly found in Catalonia Spain and California. Highly aromatic, fruity, and mild. Perfect for cooking.
Arbosana – A small olive with a robust flavor profile. Complex flavors with a peppery finish.
Manzanilla – Typically used as a table olive and picked green, it is also used for olive oil.
Picual – Provides a nice level of bitterness with a pleasant pungent finish.
Lucca – Developed by UC Davis
Mission – A dual purpose olive used for both table olives and olive oil. The olive oil tends to be delicate in flavor.