In Part 1 of this blog post about the adulteration of olive oil, I gave you some reasons for caring about the quality of your olive oil. Assuming you do care, you will want to determine if your favorite olive oil is an imposter or the real thing.

All of the websites I’ve read, said the first step is the fridge test. The fridge test won’t prove that your EVOO is pure, but it will indicate if it’s been cut with poly-unsaturated oils.

Pure monounsaturated fat, also known as oleic acid, solidifies at 39 degrees F. Since olive oil is primarily oleic acid (about 70-85 percent, generally), sticking a bottle of real olive oil in the fridge should elicit solidification. The original olive oil adulterants, sunflower oil and safflower oil, were mostly polyunsaturated, so adulterating olive oil used to be easy to spot. Now, with high-oleic sunflower oil, high-oleic safflower oil, and high-oleic canola oil on the scene, adulterated olive oil can still solidify in the fridge. Thus, the fridge test is still a necessary, but not sufficient, test for the legitimacy of your extra virgin olive oil. It’s really a test for the degree of monounsaturation in the oils. It’s important (toss any oils that fail the test), but it’s not the full story.

Read more:

I decided to test three brands of Olive oil: Spectrum Organic EVOO, 100% Organic Colavita EVOO, and Filippo Berio EVOO. The Colavita EVOO states that it is Certified Authentic Product of Italy. “Obtained exclusively from olives harvested & pressed in Italy. The CERMET seal certifies the authenticity of Colavita EVOO. Colavita was the first Italian company to receive this important certification declaring it’s extra virgin olive oil as 100% Italian.” I put olive oil in three containers and set in the fridge over night. I did the test twice, switching around the containers. I got the same results both times as shown below.

The Spectrum Organic EVOO was completely liquid. There was not a fat globule to be found. The Berio EVOO had fat globules in it but it was still liquid. You can see some of the globules on the sides of the glass in the photo below. The Colavita EVOO was completely solid.


My olive oils at the start of my experiment.


My three olive oils after overnight in the fridge.

Mark, from Mark’s Daily Apple, whom I quoted above, suggests throwing out any EVOO which stays liquid over night in the fridge. I will keep it to clean my grill. Luckily, I only bought a small bottle of the Spectrum Organic. I use Spectrum’s Organic coconut oil which is now suspect as well. 8-(

My friend, Laurel Dodge (author of Nature Study for the Whole Family), had the following results:

Newman’s Own Organics: Organic Extra Virgin Olive Oil (ingredients say extra virgin olive oil from Tunisia): cloudy and thickened.

Bertolli Olive Oil for Sautéing and Grilling: (ingredients say refined olive oils and virgin olive oils): clear and same consistency.

If you test your EVOO, be sure to post your results in the comments sections!

Upon further reading at Olive Oil Times, it gets even more muddied in that factors including the variety of olive used and the time of harvest will determine if the EVOO solidifies at cold temps.

The next step is a taste test. EVOO should have a spicy, pungent flavor. If you’re used to mild, adulterated EVOO, the good stuff might taste odd! Ultimately, Mark suggests to buy locally and know where your EVOO comes from!

The final advice from the Olive Oil Times?

Flynn advised viewers of the Dr. Oz show to check the harvest date on the olive oil bottle, and buy one indicating a harvest within the last 15 months to improve the chances of getting a good quality oil. He also recommended looking for quality seals on the bottles, such as the one from the California Olive Oil Council, that certify that the oil has passed chemistry and sensory criteria. Flynn noted that UC Davis is working on better methods of detecting olive oil fraud.

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I am a busy mom of three, former scientist and homeschooler, soccer mom, and also a franchise-at-home entrepreneur. Come along with me on my journey to minimize the effects of autoimmunity and continue to be the active person I've been so I can be healthy and active as an older mom.

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