my understanding is first cold pressing only to be extra virgin. it has the most flavor and is most pure.. its the one you use on salads if you can afford it!. long cooking with this grade is a waste as it changes the flavor. unless its added at the end of the cooking or just before serving.. . below is from Internet... . . . Since IOOC standards are complex, the labels in stores (except in the US -- see below) clearly show an oil's grade:. . Extra-virgin olive oil comes from the first pressing of the olives, contains no more than 0.8% acidity, and is judged to have a superior taste. There can be no refined oil in extra-virgin olive oil.. . Virgin olive oil with an acidity less than 2%, and judged to have a good taste. There can be no refined oil in virgin olive oil.. . Olive oil is a blend of virgin oil and refined virgin oil, containing at most 1% acidity. It commonly lacks a strong flavor.. . Olive-pomace oil is a blend of refined pomace olive oil and possibly some virgin oil. It is fit for consumption, but it may not be called olive oil. Olive-pomace oil is rarely found in a grocery store; it is often used for certain kinds of cooking in restaurants.. . Lampante oil is olive oil not used for consumption; lampante comes from olive oil's ancient use as fuel in oil-burning lamps. Lampante oil is mostly used in the industrial market.