Chances are, your olive oil is an imposter. A report published by the University of California, Davis, in 2010 found that 69% of imported olive oils labeled as “Extra Virgin Olive Oil” were either not extra virgin olive oil, were rancid, or were adulterated with other cheaper oils. They studied 52 samples from 14 of the top selling brands in California to reach these conclusions. The imported brands were the most frequent offenders. The tested California brands had a fail rate of only 10%. This is the pdf of the original 2010 report from UC Davis.
Check out this NY Times infographic called, Extra Virgin Suicide. which explains how and why imported oils are adulterated with cheaper ingredients. Short, informative (and entertaining) to click through.
A follow up study (as pdf) by UC Davis was done in 2011 to expand on the original by taking more samples of fewer brands, for more accurate results. This was sponsored by a few of the leading California brands that tested well, by the way.
Here are the brands whose samples failed the extra virgin oil tests:
- Filippo Berio
- Newman’s Own
- Whole Foods brand olive oils
- Pompeian Olive Oil
And, here are the winners:
I did a little more research to learn about how to shop for olive oils. There is some consensus that olive oils confer the best health benefits when they are fresh, preferably less than 18 months old. Low temperature cooking is fine for culinary reasons, but the health effects come from consuming it raw: drizzle it over salads, or use it as a dipping sauce. The taste should have a fresh, fruity or even “grassy” flavor with at least a slight pepper-spice sensation in the throat. (Some can actually feel quite spicy!)
The takeaway message here is to avoid buying imported olive oil, unless you really know and trust your source. If possible, look for olive oils that are less than 18 months old, and preferably contained in darkened glass bottles. Organic domestic brands might be your best bet, for freshness, taste, health benefits, and for general safety.