Extra virgin olive oil is the backbone of the Mediterranean diet and lauded for its health benefits. But when it comes to cooking with it or drizzling it on our food, is there really a difference between a generic bottle that you can get for $5 and a $39 estate oil made with a single olive variety?

First, know this: Many cooking experts believe extra virgin olive oil is meant to be consumed drizzled on foods or mixed into dips, not cooked (though this is a point thats recently been argued against). Extra virgins low smoke point makes it susceptible to turning bitter, and regular olive oil is often a better choice for everyday cooking.

Second, its important to understand that in order for an olive oil to be labeled extra virgin, it must pass chemical and sensory tests that act as indicators of quality. Specifically, it must be an oil with zero sensory defects and a free fatty acid content of less than 0.8 percent , which are standards set by the International Olive Council in Madrid. The tests are performed by labs and specially trained sensory panels (ideally recognized and certified by the likes of IOC or the American Oil Chemists Society ).

Like a lot of grade standards, the tests are set at a minimal level of quality, said Dan Flynn, executive director at UC Davis Olive Center . On the chemistry, what weve found is that the standards at least at the international level are set fairly permissively so that you could pass without that much trouble.

While the majority of oils labeled extra virgin will undergo relatively fast and inexpensive chemical tests, most wont be scrutinized under the more costly sensory test before it reaches shelves. This means that not only is there a wide range of quality in the extra virgin olive oil category, but there are oils out there that shouldnt even be labeled extra virgin in the first place.