The  state Department of Food and Agriculture approved new quality standards for olive oil last week. This will require California-produced olive oil to be tested for purity, and producers must also prove that their product is truly extra-virgin.

This is a major victory for state olive oil makers who regularly compete with European importers, which make up 95 percent of olive oil consumed in the United States, says Jeff Colombini, chair of the Olive Oil Commission of California, the organization that recommended the new standards. 

Colombini says USDA standards weren't enforced and European importers knew that, "so typically, they will import non-extra virgin olive oil and label it as extra virgin oil, essentially deceiving consumers... The olive oil industry is a relatively young industry in California and we do produce, almost exclusively, high quality extra virgin olive oil."

And, the only way to ensure that is to have mandatory testing of all olive oil made in the state, Colombini says.

So, how do you tell the difference between what's real and what's not?

"The first difference [can be determined through] an object chemical analysis that is done in terms of free fatty acid levels and peroxide values, etc., and then there's a taste panel that taste the olive oil to make sure it's free from flavor defects," Colombini says.