My Olive Oil Fridge Test...Who Passed?

After reading multiple posts this summer about the Extra Virgin Olive Oil controversy, I decided to investigate my olive oils for authenticity.  Of course, we have no foolproof way to do so (I don't have access to a mass spectrometer, LOL), and there is no home test that can guarantee your bottle of EVOO is in fact pure, unadulterated olive oil.  But I felt that the refrigeration test was the best option.  If your olive oil crystallizes/solidifies it isn't a guarantee that no other oils are present, but if your olive oil does not at all crystallize, it tells you that there is no decent olive oil in that bottle.


I apologize for my brevity, but life is just beginning to become normal again after a miscarriage, so I am not my usual verbose self.  I'll just give you a quick rundown of my findings.  

[Background blurb:  Years ago, when we lived near Salt Lake City, we shopped at a boutique gourmet shop that carried high quality food imports and heirloom produce.  If you're ever in the city, check out Liberty Heights Fresh...it's worth the trip!  We used to purchase French, Italian, Spanish and Greek EVOOs there and they were excellent.  The shop owner often traveled to his producers and maintained relationships with many of them.  I believe he and they are to be trusted.  I know many articles say it is impossible for consumers to discern by taste whether their EVOO is adulterated, but I would disagree.  If you spend years eating nothing but the best authentic EVOO, you do develop a palette for it.  Since leaving the SLC area, and living in and leaving the SoCal area, we have purchased a wide variety of EVOOs from gourmet shops, online stores, Trader Joe's and health food stores.  I have been able to discern flavor differences that made me suspect the less expensive oils, as I will mention below.]

OK.  I only have a couple snapshots to demonstrate my experiment; I apologize.  I took samples from a few bottles of EVOO I had on the shelf and I refrigerated each of them for 24 hours.  The following are my results:

12 hours.  L: Bionaturae, R: Napa Valley, Top: Bariani

My sample of organic Spanish EVOO from Trader Joe's did NOT solidify at all, not even after 48 hours.  I gave up and forgot to take a photo.  I have purchased various TJ's oils over the years and have noticed the flavor to be bland.  I only had the Spanish bottle left in my pantry, so tested it.  I'm ruling it a fake and no longer buying it (and likely won't buy TJ's EVOOs at all.  Sometimes you do get what you pay for).

24 hours.  L: Napa Valley, R: Bionaturae, Top: Bariani

My samples of Napa Valley Organic Extra Virgin Olive Oil (Italian blend) and Bariani Californian EVOO (I purchase at Live Superfoods) turned semi-solid within 12 hours.  My sample of Bionaturae Organic Extra Virgin Olive Oil (Italian blend) was beginning to crystallize after 12 hours, but did not actually become semi-solid until spending 24 hours in the fridge.  

Of all the oils, the Bariani tasted the most authentic to me, with a strong peppery finish.  The Bionaturae oil's website describes the company's hand harvesting and same-day pressing process, and the information presented is appealing.  I cannot be assured completely that my three "winners" are indeed nothing but pure, uncut EVOO, but I'm hopeful that they are.  

Kirkland organic EVOO

The biggest disappointment was my Kirkland (Costco brand) organic EVOO.  This oil was one of many tested by UC Davis in July 2010; at that time it was determined to be pure.  I have bought this oil for a couple years to use in my medicinal herbal salves.  When I refrigerated the bottle for a week, there was hardly any crystallization at all, just slight cloudiness.  When I studied the refrigerated herbal oils I had prepared with Kirkland oil, I found that last year's oil was nearly solidified but my recent batches (with oil purchased this spring) were much more liquid.  If the refrigeration test can tell us anything about EVOO authenticity, I suspect a degradation of Kirkland EVOO quality since the 2010 testing.  Again, my experiment is not conclusive either way, but I am looking for some guideline to use in my future EVOO purchases.

Last year's Kirkland EVOO

This spring's Kirkland EVOO

Keep in mind that when purchasing from large vendors and companies that buy from middle men, EVOO qualities will change from season to season, even batch to batch.  Companies like Costco, who buy in vast quantities, are purchasing oils from multiple orchard sources.  Companies like Trader Joe's do the same...purchase vast quantities of oils from multiple suppliers and then repackage with their label.  So genuine EVOO quality could be hit and miss in these cases; it certainly won't be predictable and static.  Purchasing from smaller companies with traceable supply sources, or directly from an orchard or a vendor who works with single orchards, is a consumer's best option.