There are many types of olive oil so how do you choose? Olive oil is extracted by either pressing or crushing olives.
Depending on the type of processing or refining, you will get different quality of oil.
... And quality will dictate the price of olive oil.
Extra Virgin Olive Oil (or EVOO) - is cold-pressed oil and is considered the best oil. "Virgin" olive oil really signifies that it was obtained from the fruit of the olive tree solely by mechanical processes that cause no alteration or deterioration through heat or chemical interaction. As such, it cannot undergo any refining process other than washing and filtration processes.
Extra-virgin olive oils must have an acidity of less than 1%. Because EVOO is the least process, it is considered the best oil to use on a daily basis for cooking and for home remedies. When purchasing you will want to buy the best quality EXTRA-VIRGIN olive oil.
Virgin Olive Oil - is from the second processing. Virgin olive oils may have an acidity between 1 and 2%.
Pure Olive Oil - is a combination of extra virgin olive oil with refined olive oil. As such, it is a lesser grade than the pure extra virgin olive oil and is labeled as just "olive oil" in the United Stated.
Extra Light Olive Oil - undergoes a considerable refining process.
Light Olive Oil - is not really talking about a GRADE of olive oil but is just a market concept. There is no standard or certification process and therefore, is completely unreliable.
Fino Olive Oil - like extra virgin olive oil, Fino or fine olive oil is also cold pressed oil and has an href="http://www.health-benefits-of-olive-oil.com/olive-oil-glossary.html">acidity level of 1.5% or less.
Infused Oil - adds fun and flavor to your cooking... there are varieties to choose from such as Bergamot, Pepperoncino, Lemon, Basil, Oregano, Rosemary, Garlic, Truffle, and Porcini.
Good quality oils are produced when the olives are crushed or pressed as soon as they are harvested. Any type of storage would trigger a fermentation process in the fruit, which would increase the acidity over time as well as produce undesirable effects in both flavor and aroma.
If they are processed properly, even virgin olive oil would maintains the purity of the fruit's flavor, aroma, and nutritional properties.
Therefore, it is better or even recommended to use pure olive oil for frying, since the flavor of extra-virgin olive oil tends to break down at frying temperatures.
There's definitely no need to waste your good quality and possibly expensive extra virgin olive oil for frying. Therefore, it's important to know the grades and different types of olive oil that are out there before making your purchases.