Olives in Zaforas

Where is Olive Oil produced?
The olive oil tree flourishes in Mediterranean-type climates (between 30-45th latitudes) with hot dry summers and cool winters. The trees are sensitive to the cold during the growing season, but are able to tolerate drought and heat. Olive oil production is still mostly centered in the Mediterranean region, although in recent years we are beginning to see olive oils from regions throughout the world.

Spain with over 300 million olive trees is the number one producer of olive oil at 35% of world production, with 75% of that coming from Andalusia. Spain was the first country to establish a "Denominacion de Origin" for olive oils. The types of olives grown in Spain are the arbequina and verdial varieties of Catalonia, and the hojiblanca, piqual, cornicabra, and lechin varieties of the south. The piqual variety of the south accounts for 50% of all olive trees in Spain.
The second largest producer with 24% of worldwide production is Italy. Italians who consume 10 quarts of olive oil per person per year do not produce enough oil for their domestic consumption, yet they are one of the largest exporters of olive oil in the world. Much of their oil is imported, bottled and exported as an Italian product. Spain is their major supplier.
Greece is the third largest producer with 19% of the world production. French olive oil production, which is mainly focused in the Provence region, is only a small percentage of worldwide production. California has also recently been recognized as an up and coming olive oil producer. Other countries that produce significant amounts of olive oil are Tunisia, Turkey, Libya, Argentina, Morocco, Algeria, and Portugal.

How is Olive Oil produced?
The Harvest season is from September to March depending on the region and whether the fruit will be used for oil or table olives. Olives are hand picked to ensure that the fruit is at its optimum ripeness and to reduce bruising. Unripe olives, which are pear shaped and green, will change to a dark purple and then black as they ripen and "fill" with oil. In Spanish this maturation process is called envero. Olives can be processed for oil at any time, but ripe olives will yield more oil and it will be less bitter. Like wine, the conditions and treatment of the olive tree throughout the year will have an effect on the yield and quality of the oil.

Once the olives have been picked they may be allowed to remain in piles for a short time to increase the heat in the piles, which helps to release more oil. But production should take place fairly soon after picking to reduce the chance of fermentation of the olives. In Spain, olives designated for "virgin" oil must, by law, be pressed within 72 hours of harvesting.
The newly harvested olives are first sprayed with jets of cold water to remove impurities and any leaves still hanging on. The olives are then ground, a process called tritulation, to shred the flesh and crush the pits. This helps to release the oil. The resulting paste (traditionally made from hemp called esparto), which are stacked one upon another and placed into a hydraulic press to undergo hundreds of tons of weight. The resulting reddish-brown liquid consists of part olive oil and part natural olive vegetable water.

The oil is then centrifuged to separate the two. Some producers will collect the oil that results solely from the weight of the olive paste before it is pressed. This first-run oil, referred to as yema flor in Spanish, is of the highest possible quality.

The process described is called the first cold pressing, in which the oil is obtained without heat or chemicals. A batch of ten pounds of olives will produce about one quart of oil. With this process, 90% of the oil is extracted with the first press. The paste is sent to the refinery to remove the remaining 10% , or pomace oil. Historically when the olives were hand milled, much less of the oil was obtained from the first pressing. Second pressings and hot-pressing techniques were then used. Today this is no longer necessary, but many producers will still use the "first cold-pressed" terminology on their labels.

Read more of this entry in Matiz: Spain Culinary Tour