Wild olive trees originated in Turkey and eventually spread all over the Mediterranean, where they were cultivated for the production of olive oil and olives. The production of olive oil dates back to Neolithic times at about 4500 to 4000 BC in ancient Israel and on the Greek island of Crete.
Olive oil was widely used for cooking and fuel as well as for religious, medicinal, and cosmetic purposes in ancient civilizations around the Mediterranean.
Today, olive oil is consumed worldwide, with Greece, Spain and Italy both the biggest producers and consumers. Scientific studies have shown that a diet rich in olive oil, which contains high amounts of monounsaturated fat and antioxidants reduces the risk of cardiovascular disease. This is especially true for extra virgin olive oil, which undergoes the least amount of processing.
What To Look For
The vast majority of olive oil production is governed by the International Olive Council (IOC), an intergovernmental organization based in Spain. Most of the world’s olive oil is produced by the IOC’s twenty-three member states.
The US is not an IOC member state, and the US Department of Agriculture currently does not acknowledge the IOC’s quality standards. The IOC provides strict regulations for commercial and retail classification of olive oil into different grades . Retail grades must be shown on product labels. Olive oil is defined by the IOC as “oil obtained solely from the fruit of the olive tree”.
Commercial olive oil grades typically refer to the extraction and processing method:
- Virgin olive oil is produced solely by physical extraction of oil from the olive fruit. No chemical treatment was applied.
- Refined olive oil has been chemically treated to eliminate unwanted flavors and acidity.
- Pomace olive oil is produced from the leftovers of physical extraction by applying chemical processes.
Retail olive oil grades (IOC definitions):
- Extra virgin olive oil is derived exclusively from virgin olive oil production (physical extraction only) and cannot contain any inferior quality oils, such as refined or pomace oil. Its acidity is less than 0.8%.
- Virgin olive oil is derived exclusively from virgin olive oil production (physical extraction only) with an acidity of less than 2%.
- Pure olive oil and olive oil are blends of oils derived from virgin and refined production methods.
- Refined olive oil (see commercial grade oils above)
IOC quality standards and definitions do not apply to olive oil sold in the US (including imported oils) therefore terms such as “extra virgin olive oil” may be applied to products that are not defined as such by the IOC. It is perfectly legal in the US to sell refined olive oil as “extra virgin” olive oil.
The US Department of Agriculture has defined four grades of olive oil based on acidity and defects, ranging from U.S. Grade A or U.S. Fancy to U.S. Grade D or U.S. Substandard. These grades do not provide any information about the extraction process, which is the most important quality indicator for olive oil.
It is important to note that the geographic origin of the olives and the bottling location may not always be identical. For example, olive oil from Turkey may be bottled in Italy, and consumers need to pay close attention to product labeling. While this is not an issue with high quality oils from “boutique” producers, it is often the case for mass produced cheaper brands that are widely available in grocery stores.
In the European Union (EU) olive oil from olives which have been grown, harvested, and processed in a specific geographic region is labeled with a “Protected Designation of Origin” (PDO) seal. Paying attention to labeling as well as purchasing oils from individual growers are the best guarantees for superior quality.
Labels often contain intentionally misleading phrases or words. Phrases such as “first press” and “cold pressed” are particularly problematic, because there is no “second” press in the mechanical production of olive oil, just as the term “cold” is not an indicator of quality or production method as mechanically extracted olive oil is always “cold pressed”.
In different parts of the Mediterranean, olives are harvested at different times of the year and thus at different outside temperatures. Mechanical extraction is always undertaken at the lowest possible temperature and generally at no more than 35C.
- Always look for the extraction process on the label. It is the most important quality indicator.
- Extra virgin olive oil (physical extraction only; less than 0.8% acidity) is superior to all other types of olive oil.
- If possible, purchase olive oil with a PDO seal in order to ensure the actual origin of the olives.
- Buy from small individual growers rather than commercial brands.
How To Use It
High quality extra virgin olive oil has a distinct flavor, color, and smell depending on the types of olives used, their geographic origin, and the time of harvest. It is common for individual producers of superior quality oils in Mediterranean countries to invite customers to an “oil tasting” akin to a wine tasting.
In order to appreciate the typical flavor of gourmet extra virgin olive oil it is best used cold for salads, salad dressings, and cold dishes, or drizzled on slices of crusty Italian bread that are dipped in freshly grated Parmigiano Reggiano. Heating extra virgin olive oil above a certain temperature (350F/177C) results in the disintegration of the oil and destroys its unique flavor. Extra virgin olive oil should never be used for deep frying or even sautéing.
Olive oil should not be exposed to light and therefore should be kept in a dark container or place. It has a limited shelf life and the fresher the oil, the better its taste. A small decanter works best for serving extra virgin olive oil at the table.