The olive oil section of the store may seem overwhelming. Some places have a large selection of oils in a wide variety of prices. How do you know what kind you will like best and what type is best for you? Learning the grade and source can help.

The International Olive Oil Council (IOOC) has developed a series of “grades” for olive oils. The grades refer to the taste, acidity, and way the oils are produced.

While the grades of the IOOC are similar to those used in the United States, they are not exactly the same. How Stuff Works nutrition writer Gayle Alleman explains the U.S. Department of Agriculture (USDA) has graded olive oil for longer than the IOOC has been around. So, the USDA kept its system.

Many factors will affect the quality of olive oil including the part of the world in which the olives were grown, the time of year they were harvested, and the way in which the olives were harvested and processed. Storage and packaging can also make a difference in taste.

The USDA has five basic grades of olive oil:

1. “Extra-virgin olive oil” is considered to have an “excellent” flavor based on fruitiness and odor. It also has a lower oleic acid content than the next grade – virgin olive oil.

2. “Virgin olive oil” is slightly lower in quality of odor and flavor, but has a higher fatty acid content, which actually could make it better for your health.

3. “Virgin Olive Oil Not Fit for Human Consumption Without Further Processing” is the third grade of oil. It has the same fatty acid level as virgin olive oil, but it requires further refining because of its poor odor and flavor.

4. The fourth grade of olive oil is "U.S. Olive Oil” which is actually a blended product. Again, it has a lower oleic or fatty acid content. It has vitamin E levels of 200mg/kg.

5. “U.S. Refined Olive Oil,” the fifth grade, has the lowest level of oleic acid and has vitamin E added.

Olive-pomace oils is a separate category of olive oils which are not allowed to be labeled as “olive oil” in the United States.

Related Articles:

Fish Oil, Omega-3 and Preventing Heart Attacks

Olive Oil Fights Diabetes: Study