Saturday 30 May 2009

What is extra virgin olive oil?

Extra virgin olive oil is a classification of olive oil. It is the oil from the first pressing of olives by mechanical (not chemical) means. Only cold extraction is allowed as a technique. Extra virgin olive oil has naturally low levels of free oleic acid; the content must be less than 0.8 percent to qualify as extra virgin olive oil. The lower levels of free oleic acid means there is less oxidization of the olive oil.

What does the color reveal?
The colors of extra virgin olive oil can range from bright green to soft golden.
Color can also vary with the type of olive, when it was picked and growing conditions.
Generally, the darker, more intense the color, the flavor will be more fruity and assertive; however, this is not always a reliable rule of thumb.
Unethical producers can crush a high percentage of leaves with the olives to obtain a greener coloring.

What is the best way to store it?
Store upright, in an air-tight container, in a cool, dark place.
Do not store near a stove or on windowsills since direct light and heat will damage the oil.
If you place oil in the refrigerator, it will become cloudy, solidify, and lose its aroma.

What is the shelf life?
It is best if consumed within a year and a half of its harvest date.
Unfiltered oils because of their sediments should be consumed more quickly than filtered oils.
Younger and fresher olive oils are more intense and pungent.
As extra virgin olive oil ages, its fruity flavor mellows.
Mass-produced, lower-grade olive oils have higher acidity and tend to become rancid more quickly.
Extra virgin olive oil, unlike classic red wine, does not improve with age.

Choosing an extra virgin olive oil
Choose an extra virgin olive oil as you would choose a wine and look for labels with the name of the producer.
Useful information includes the variety/varieties of olives and the specific region the olives are grown, and most importantly, the harvest date.
Much like wine, extra virgin olive oils are pure expressions of "terroir", reflecting the soil composition, climate and types of olives used by the producer.
Different regions of Italy produce oils with different tastes. For example:
Ligurian extra virgin olive oil is light and delicate with a buttery taste.
Best used for homemade pesto and mayonnaise; drizzle over delicately grilled or poached fish or seafood stew.
Tuscan extra virgin olive oil has an herbaceous taste with a pungent, peppery bite. They are robust and somewhat spicy. The characteristic green color is due to the early harvesting date (to avoid early winter frosts).
Traditionally paired with fettunta (grilled bread), boiled beans, and farro salad.
Sicilian extra virgin olive oil is somewhat grassy and robust like a Tuscan oil; however, it is generally rounder and has a more pronounced fruit flavor Use with fresh greens, grilled vegetables and medium flavored grilled fish.

Continuous Cycle Production Method
Advances in today's olive oil processing allows for increased quality and longevity of olive oil. Contemporary pressing equipment also allows for better yields and the opportunity to create or enhance the flavors of the oil as the fruit is being processed. Old methods with their natural straw mats and filtration through cotton batting or muslin left the oil exposed to bacteria and other contaminants, which leads to quicker oxidation and rancidity of the oil. The old clay vessels used to store the oil after pressing, allowing it to settle before bottling, also left the oil exposed to any number of things in the porous interior of the clay. Those vessels have been replaced with stainless steel storage tanks, again lessening the possibility of exposure to outside environmental factors.

State of the art equipment employing the continuous cycle process protects the olives from outside contaminants from the time the fruit is washed until oil is extracted and separated from the olive liquid. Continuous cycle methods vary with type of equipment used, whether the fruit is crushed with stone wheels into a paste, cut with sharp stainless steel blades, or centrifuged to separate oil from liquid or gravity separation. Each of these processes is crucial to the integrity and quality of the oil that is produced.

Step One: Freshly harvested olives are washed and cleaned of as much twigs, leaves and other debris as possible.
Step Two: The fruit is then added to the hopper. The mixture is ground into a paste with either stainless steel teeth that grind the fruit into pieces or stainless steel hammers with centrifugal action push the olives into the sides of the rotating chamber. This action will pulverize the olive fruit into small pieces.
Step Three: The mixture is then seamlessly transferred into a malaxer, ahorizontal trough with a spiral-mixing blade. Through this process the small oil droplets are encouraged to form larger droplets, allowing for easier separation from the liquid material. Mixing time lasts 20-40 minutes. The longer the mixing the better the yield of paste, which contributes to improved flavor of oil.
Step Four: The pulp and oil liquids need to be separated from the paste. By spinning the mixture at high revolutions in a horizontal drum the heavier flesh and pits spin to the outside and the water and oil are tapped off in the center. Dual phase centrifuge may also be used which recycles the olive water to extract more oil from the pulp. Water, oil and pulp are simultaneously removed in a single step. This results in the highest percent of oil extraction, with less possibility for oxidaton. Olive oil from the two-phase extraction process has higher levels of phonols and tocopherols resluting in very aromatic oil with even more resistance to oxidation. Sinolea separation may also be used. Rows of metal discs or plates are dipped into the olive paste. The oil preferentially wets and
sticks to the metal and is preferentially removed with a scraper in a continuous process.
Step Five: Separation of oil and water occurs as a vertical centrifuge with perforated conical discs is spun at high revolutions separating the heavier water from the oil. The water is discarded and the oil is moved to airtight
stainless steel storage containers. At this point the oil is allowed to settle before bottling.

During the continuous cycle process, the olive fruit, paste and oil are in an airtight chamber under inert gas, such as CO2 or nitrogen. This decreases the possibility of oxidation during the extraction process thus resulting in high quality oil with a longer shelf life, great flavor and brilliancy of color.

Olio Nuovo and Novello
One of the great rituals for food-loving Italians is the annual tasting of freshly pressed olive oil. The harvest of green olives during November provides this traditional treat. New olive oil is usually called nuovo in the north, and novello in the south; both words mean new or fresh. In the case of extra virgin olive oil this means piquant, zesty, unfiltered, and completely untamed by decantation. Special bottlings of olio novello from Olio Verde in Sicily, and olio nuovo from Tenuta di Capezzana in Tuscany, arrive at Manicaretti by air in mid-December. Both estates have very limited production.

Source: Manicaretti

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