Olive oil can vary widely in flavor and color depending on the variety of olives used and the region they come from. Olives for the best olive oils are often harvested by hand, a cost that is passed on to the consumer.
Virgin olive oils. These are extracted from olives solely by mechanical means, without chemicals. “Extra-virgin” olive oil is the highest grade. Industry standards stipulate that extra-virgin olive oil must meet numerous chemical parameters and sensory standards. In a test by a trained taste panel using official protocols, an extra-virgin olive oil will have no defects of aroma or flavor, and some positive flavor of green and/or ripe olives. It is more expensive to produce because of the higher costs at each stage of production, from grove to bottle.
Olive oil simply labeled “virgin” has slight defects in aroma or flavor and has to meet lower chemical standards, so it is less expensive.
The words “cold-pressed” or “first cold press” on olive oil are archaic terminology from the era of actual olive presses; today almost all olive oil is extracted using a centrifuge. The terms are also redundant: All genuine extra-virgin olive oil comes from the first extraction, and no excessive heat is used. They still appear on some labels as a marketing ploy, but the terms are meaningless except under European Community law, which requires the use of a traditional press for such labeling.
Refined olive oil blends. If virgin olive oil does not qualify for the virgin designation as defined by its acidity level and other factors, the oil is refined to remove undesirable odors and flavors. The result is a bland, almost colorless oil that is blended with a small amount of virgin olive oil to give it some olive character. The two refined olive oil blends found in the U.S. market are:
“Pure olive oil” (also simply called “olive oil” or “classic olive oil”): This is usually a blend of refined olive oil with less than 10% virgin olive oil. It tends to have little flavor and is best used for sautéing rather than for salads.
“Extra-light olive oil”: This is a refined olive oil blend with a lower percentage of virgin olive oil, making it paler in color, with very little olive flavor. It does not mean that the olive oil is lower in fat or calories. Labels are now supposed to read “extra light (in flavor)” because of confusion over the calorie content.
Also see Is Olive Oil Really That Special?