Three types of olive oil are available as a result of refining processes:
Refined Olive Oil
Olive Oil
Olive Pomace Oil
Refined Olive Oil
Olive oil known as "Refined Oil" is obtained from refining virgin olive oil that has defects. Among the defects are a natural acidity higher than 3.3%, poor flavor, and an unpleasant odor. This "defective" virgin oil is known as "Lampante Virgin Olive Oil" and is not fit for human consumption without additional processing. The lampante virgin olive oil is treated with heat, filtration, and/or chemical processes to produce the refined oil.
Refined oil may be left as is, with no taste or color, or it may be blended with virgin olive oil to provide some flavor and aroma and sold as "Olive Oil" or "Pure Olive Oil". Refined oil that is not altered after the refining process is used for commercial purposes such as for packing sardines or smoked oysters. Refined oil has the same calories and health benefits as the better grades of olive oil, but it has no flavor. The acidity level cannot exceed 0.3% (before the addition of virgin or extra virgin oil) in order to be classified as refined oil.
Olive Oil
As mentioned, "Olive Oil" or "Pure Olive Oil" is a blend of refined oil and virgin or extra virgin olive oil. Refined oil has no taste or smell, so the virgin or extra virgin olive oil is added to provide both.
Products labeled "Olive Oil" or "Pure Olive Oil" usually have a ratio of 85% refined oil to 15% virgin or extra virgin olive oil. "Olive oil" is less expensive and has less flavor and aroma than higher grades of olive oil. The maximum acidity level may not exceed 1.5% (after the addition of the virgin or extra virgin oil) in order for the oil to be designated "Olive Oil" or "Pure Olive Oil". The "Olive Oil" grade has the same health benefits of the higher quality virgin and extra virgin grades. It also has a higher smoke point than virgin or extra virgin oil, making it an excellent choice for cooking.
Olive Pomace Oil
Another source of oil designated for refining is oil that can be obtained from the residue resulting from the "first cold pressing". Up to 90% of the oil is obtained from the olives during the first cold pressing and the remaining 10% is extracted from the residue in refineries that use heat and chemical processes to obtain the oil. The level of acidity may not exceed 1.5% after the refining process. A small quantity of virgin olive oil may be added for flavor and color. Olive pomace oil is the lowest grade of olive oil approved for human consumption and it is not widely available to the consumer. It is most often used for commercial purposes.
