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  • Writer's pictureMaureen Diaz

The Olive Oil Dilemma: Are You Buying Fake Olive Oil?

Updated: 7 days ago

In a world swimming in edible oil confusion, the authenticity of Extra Virgin Olive Oil (EVOO) only muddies the waters further, making it difficult to know just what we should be using in our kitchens and serving our families. Here we will explore various means of distinguishing authentic from adulterated brands, so that we can feel confident in our choices.

What's all the fuss about?

Since the publication of Tom Mueller’s book Extra Virginity: The Sublime and Scandalous World of Olive Oil in 2012, it has become fairly well known that most olive oil on the market today, at least 70%, is in fact adulterated with cheap, industrialized seed oils such as soy and canola, as well as highly processed (often solvent and heat-extracted) olive oils. In fact, Mueller makes the claim that at least 75-80% of US imports are fake. Even expensive, high-end brands found in specialty stores very often have cheap seed oils added as well. This is done primarily in the very countries best known for EVOO production including Italy, Greece, and Spain, and thus little confidence can be derived from country of origin. It is even rumored that in Italy, well known for its olive groves and use of this delicious oil in traditional cuisine, parents often question and require proof of authenticity of olive oil being used in their children’s school lunches. If the Italian mamas need to know, so do I!

Testing, raids, and more testing

Back in 2018 UC Davis conducted testing on 8 big brands of EVOO, 124 tests in all; in excess of 70 of these imported oils failed the test. And in 2008 Italian authorities investigated adulteration within the industry (Operation Golden Oil), finding massive fraud, ultimately arresting 63 individuals (many, suspected mob-related) while confiscating a total of 85 farms.

The Italian mafia has actually found it more profitable to move fake or adulterated olive oil, labeled as “Italian Extra Virgin Olive Oil”, raking in millions in profits without any of the risk involved with drug trafficking. Italy’s Minister Agriculture Minister, Teresa Bellanova, suggested in 2019 that the cost of this illicit trade to the country was in the neighborhood of $120 billion-a massive loss of revenue for legitimate farmers and producers.

It is very revealing that while Italy is the world’s largest exporter of EVOO, in fact only about 15% of all that they export originates from within its borders. In other words, Italy is importing the vast majority of what they are bottling and labeling as, “Italian EVOO”. Is it any wonder fraud is so prevalent?

And it’s not just Italy; in fact, massive fraud within the industry is prevalent world-wide. Brazil, for instance, in 2016 seized 16,000 liters of fraudulent oil. Portugal, Spain, Tunisia, Greece-all are known to mix health-damaging seed oils in their products, or export them to Italy where these suspect oils are mixed and bottled as pure Italian EVOO.

The OGO investigation mentioned above prompted the Australian government to get very serious about testing the EVOO’s that they were importing. What they found is devastating: 100% of these oils failed their stringent tests.

Not only is adulteration is a problem; other critical factors in determining Extra Virgin status, or lack there of, include oxidation resulting from exposure to excess heat, light, and age, as well as poor-quality olives and improper storage.

How do we know if our EVOO is pure?

While there are several methods that many believe to be accurate, if not definitive, to detect adulteration and rancidity (another serious issue with EVOO), most have in fact been proven completely unreliable.

The first means by which many believe to determine authenticity is taste. Journalist Alex Renton shared this experience with a panel of experts:

“I conducted a blind tasting of extra virgin olive oils a few years ago for a national newspaper that wanted “the truth on expensive olive oil”.

We had a dozen oils, and a panel consisting of an importer, an Italian deli owner and a couple of eminent foodies: the results were so embarrassing and confusing the piece was never published. The importer went into a fugue after he was informed that he’d pronounced his own premium product “disgusting”; the deli owner chose a bottle of highly dubious “Italian extra virgin” as his favorite (it had cost £1.99 at the discount store TK Maxx); and both the foodies gave a thumbs-up to Unilever’s much-derided Bertolli brand.” (source)

No need to expand upon this: I think we can toss the notion that our taste buds can determine adulteration or authenticity is completely unfounded. Besides, there are such things as artificial additives that mimic, for instance, the flavor of phenols (naturally-occurring plant-based steroidal compounds). So let’s set taste-testing aside and move on to the next, the “cold test”.

It has become popular in recent months to test olive oil for adulteration by simply placing in the refrigerator for a period of time. Purportedly, if the oil becomes cloudy and thick, this is an indication of the presence of mono-unsaturated fatty acids that are inherent in EVOO. However, there are two main problems with this method.

First is the fact that olives contain natural waxes which, when the oil is chilled, provide much of the above changes. Some olives contain a larger percentage of these waxes, and so even when diluted with fake or highly processed olive oil the results will be the same.

Another problem with the “Fridge Test” is that many producers  chill and filter their oils to “winterize” them so that they remain fluid even in colder climates. The filtering removes much of the wax, thus rendering the oil far less likely to cloud up or thicken.

There also are a variety of lab tests used to authenticate olive oils, but performed singularly results are iffy at best. According to Wikipedia,

“The detection of olive oil adulteration is often complicated with no single test that can accomplish the task. A battery of tests is employed to determine olive oil authenticity and identity of the adulterant. Included in this testing regime is the determination of free acidity, peroxide value, Ultraviolet light extinction, fatty acid composition, sterol composition, triglyceride composition, wax content, steroidal hydrocarbons, and the Bellier test.[5] Methods employing chromatography/mass spectrometry and spectroscopy are also used to detect adulteration of olive oil.” (source)

The type of testing involved is expensive and labor-intensive, but is the best way to determine if any oil is authentic, short of knowing your farmer/producer.

Answers for the wary consumer

As mentioned earlier in this article, certainly where it is an option going directly to the olive grove is often the best way to ascertain truth in labeling. But most of us do not live in olive-producing climates and so a few guidelines may be considered before you put down any amount of money for your “liquid gold”. These include:

  1. Cost: While cost alone does not determine purity, as many of the problems associated with deception within the industry occurs within a hefty price point-and even at specialty olive oil stores, a $5 or $10 bottle at your local retailer is likely not true Extra Virgin Olive Oil.

  2. Extra Virgin: Only purchase olive oil labeled "Extra Virgin Olive Oil" or "Virgin Olive Oil" as this labeling term is regulated by the industry and denotes that it is un-heated and un-refined, ensuring the highest quality.

  3. Certifications: Programs such as the North American Olive Oil Association, California Olive Oil Council, or Extra Virgin Alliance provide the assurance needed to be certain of quality.

  4. Single source: When labels state that an oil is produced and bottled from a single grove, the probability of the oil’s purity, while not fully assured, is likely reliable.

  5. Country of Origin: Australia, Chile, and California are very serious about truth in EVOO labeling and can be relied upon to provide an honest product. This does not, however, mean that oils sourced from these locations but bottled elsewhere can be trusted for accuracy or honestly in labeling.

  6. Bottling: As olive oil is sensitive to light and oxygen, only purchase olive oil in dark glass bottles, tins, or containers.

Additionally, look for “Hand picked” and  “Cold pressed”. Ignore the “Best by” date in deference to “Pressed on”. Even “Bottled on” is untrustworthy as the oil could have lingered for many months-or more-in a tank, suffering oxidation and general deterioration. EVOO is best used within 12-18 months of being harvested, and recommended to use within 6 months of opening the bottle.

While testing must continue regularly to verify authenticity, the below brands are a few to be trusted, at least at the time of this writing:

California Olive Ranch (California, Australia, or Chile sourced only)

Kirkland brand Organic Extra Virgin Olive Oil


Academia Barilla

Not to be trusted include any labeled “light” or non-EVOO, and most brands on any grocery shelf.

Where to go from here

This article is not meant to frighten you away from enjoying the tremendous health and flavor benefits of EVOO. Rather, my intent here is to encourage you to go out, read your labels, and shop wisely. True Extra Virgin Olive Oil should be enjoyed by everyone for the amazing flavor and fatty acid profiles it contains.

Below is my favorite way to use EVOO, in homemade mayonnaise.

This is my simple mayonnaise recipe which my family enjoys every day:

¾ cup good quality EVOO (we typically use Carapelli Organic Unfiltered)

1 whole, pastured egg

1 pastured egg yolk

2 tsp lemon juice or white wine vinegar

1 tsp brine from fermented pickles, sauerkraut, or kimchi (optional but good)

1 tsp whole salt (we like Redmond Real Salt)

1 tsp dijon mustard

Immersion Blender Method: Place all in a tall, narrow container and, using an immersion blender, blend for about 30 seconds to emulsify.

Blender/Mixer Method: Alternatively, place all but the oil in a VitaMix or other blender/mixer. Blend for a few seconds, then on high speed very slowly add the oil, drop by drop, until all is emulsified.

Download recipe:

Recipe Spectacularly Simple Mayonnaise
Download PDF • 321KB

Sources for this article include Epicurious, Wikipedia, Food Renegade, UC Davis, Extra Virginity, Olive Oil Times,, ACS Publications, Olive Oil Center at UC Davis, and many more.

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