oliveoil

Specialty Olive Oil Production by Paul Vossen

On the north coast of California there are several pioneer farmers planting and producing specialty olive oils for sale in top-of-the-line markets. They are attempting to conquer this “new” crop with the same spirit that popularized fine wines, goat cheese, mesclun salad mix, and sun-dried tomatoes. Olive oil, like its similar specialty gastronomic counter parts, is really nothing new. Californians have actually been producing olive oil since the late 1800s.

Thousands of acres of olives were planted in Northern California at that time (approximately 3,000 acres in Napa and Sonoma Counties remain today) but many orchards were abandoned in the mid-1900s due to competition from low cost imports, primarily from Italy and Spain.

Today a market certainly exists for olive oil, since the United States imports about 22 million gallons each year. Interest in the health aspects of olive oil is expanding and increasing demand each year. Most of this imported oil and California Oil that is now produced is inexpensive and has been refined with heat and solvents. California produces about 300,000 gallons of oil each year. Only a very small fraction of this is the gourmet treat classified as extra-virgin and sold from $10 to $40 per liter.

Many of the new olive oil producers are associated with wineries, or have a deep love for Italy and the robustly flavored cuisine of that region. They are producing specialty, finely marketed, extra-virgin oils designed to compete with the Italian imports.

The region of Tuscany in central Italy is currently regarded as the culinary king of olive oil production, world-wide. Most of the finest olive oils in the world are either produced or bottled in northern Italy. Consequently many producers have imported the same varieties, renowned for their flavor in Tuscany, into the similar climatic region of Northern California.

These varieties include: Frantoio, Leccino, Pendolino, Maurino, Moraiolo, Taggiasca, and others. They have been planted approximately 16 to 20 feet apart and trained as traditional open-center trees. All of these orchards are still quite young and do not have significant production records as yet.

Very good oils have been produced from the dual purpose Mission variety and from carefully handled Manzanillo and Sevillano varieties as well. The latter two are large-fruited table olives that may yield only 12-15 gallons of oil per ton of fruit, while the Mission and Italian varieties may produce 40-50 gallons/ton.

There are many costs associated with olive production in an effort to achieve the economic yields of 2 to 6 tons per acre on a yearly basis. Olives will survive on very poor sites with shallow soils but will grow very slowly and yield poorly. Deep soils tend to produce excessively vigorous trees, again with lower yields. The ideal site for olive oil production is a clay loam soil with good internal and surface drainage. Irrigation is necessary to produce heavy crops and avoid alternate bearing.

The site must be free of hard winter frosts because major wood damage will occur at temperatures below 15 degrees F. The growing season must also be warm enough to mature fruit before even light fall frosts (usually by early November) because of potential damage to the fruit and oil quality.

Regular pruning should also be employed to reduce alternate bearing of trees, to encourage production throughout the tree canopy, and to produce sufficient shoot growth for next year’s flowering and fruiting. Olives bear on last year’s shoot growth, which is stunted while in competition with an excessively heavy fruit load.

Olive harvest is one of the most expensive operations in the orchard. The best quality oils come from hand-harvested fruit, which generally costs $200 per ton. Many growers try to shake, rake, or beat the olives off the trees onto tarps or nets in an attempt to reduce harvest costs.

To produce the valued extra-virgin oils, high quality fruit is crushed in either stone grinders or metal hammermills. The paste is then mixed until oil droplets form and pressed in either single batch hydraulic presses or continuous flow spinning presses. One alternative is a machine that selectively removes the oil from the paste without pressing. The olive juice, which contains both water and oil, is then separated in “cream-type” centrifuge separators, finally yielding the liquid gold.

In order to make a profit after all this, the oils are bottled in beautifully decorated, etched and labeled containers of various sizes. They are marketed in the finest establishments in the United States and served by many three and four star restaurants.

The California Olive Oil Council (COOC) is a non-profit organization devoted to the education of its members and consumers concerning specialty olive oil. They conduct research, tastings, festivals, tours, and quarterly educational lectures to disseminate information regarding the cultivation, processing, distribution, and marketing of olive oil. For more information contact the COOC at 888-718-9830.

Paul Vossen is a Farm Advisor with the University of California Cooperative Extension in Sonoma County and board advisor to the California Olive Oil Council. He has traveled to Italy and Spain to gather information on olive oil production and taught the California Olive Oil Short Courses in 1993 & 1997.

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