起初并不知道橄榄油extra virgin （第一次冷压）和 light （第一次冷压后再加温热压）的区别，知道了后，再也不敢买light 了。
Extra-Virgin Olive Oil: All olive oils that are less than 1% acidity and produced by the first pressing of the olive fruit through the cold pressing process is called extra-virgin olive oil.
According to Paul Armas Lepisto, Director of The Olive University, most olive oils today are extra virgin in name only, meeting only the minimum requirement. Extra virgin is a chemical requirement that does not indicate quality and taste.
Virgin Olive Oil: It is made from olives that are slightly riper than those used in the production of extra-virgin oil. Virgin olive oil is produced in the same way, but it is essentially defective or low-grade extra virgin oil. This oil’s acidity is a slightly higher level of 1 1/2%.
Refined Olive Oil: Olive oil known as "refined olive oil" is made by refining the virgin olive oil. The final product is basically a tasteless olive oil. The acidity level is higher than 3.3%. It also has a not-to-nice flavor and an unpleasant odor.
Pure Olive Oil: Pure olive oil, usually called just olive oil, comes either from the second cold pressing or the chemical extraction of the olive mash left over after the first pressing. This grade is also called commercial grade oil. Pure olive oil is much lighter in color and blander in taste than virgin olive oil. It is a general-purpose (all-purpose) olive oil. Pure refers to the fact that no non-olive oils are mixed in.
Refined Olive-Pomace Oil: Oil which is obtained by treating olive pomace with solvents is refined using methods which do not lead to alterations in the initial glyceridic structure. Don’t buy this grade, as it is bad for you.
Olive-Pomace Oil: Olive oil which consists of a blend of refined olive-pomace oil and virgin olive oil. Don’t buy this grade, as it is bad for you.
Light & Extra Light" Olive Oil: The olive oil that you see on the supermarket shelf advertised as "light" or as "Extra Light" olive oil contains the exact same number of calories as regular olive oil and is a mixture of refined olive oils that are derived from the lowest quality olive oils available through chemical processing.