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Olive Oils - tests, reviews, commentaries, etc


I’ve always used rice bran oil for high temp - in the wok mainly … I must admit to not liking the flavour and smell as much as olive oil …

I’ve kept an eye out for oil made entirely from black olives and not seen it here - but very limited specialty shops where I live. Do you know of any? particularly that might be able to be ordered online?


Will keep an eye out for it … you might get it imported from Greece or may be Spain… not sure if any one sells it in Sydney.


It is always a good idea to check the veracity of ‘facts’ before re-posting things.

Choice did research in 2010 which found not all extra virgin olive oil was really extra virgin. (link provided by @syncretic earlier)

Unfortunately you were taken in by pseudoscience, and the article you have posted is misleading and inaccurate. (Refer to

There is no research paper to be found on this topic in Google Scholar. There is what the Olive Centre in California call a research paper (it is not peer reviewed). But, I could not establish the research credibility if any, of the Olive Centre.

So only trust research from reputable sources like Choice :slight_smile: that undertake unbiased science based studies.


For those who are interested, the original UC Davis Olive Center report can be found here.

This report concluded:

Our laboratory tests found that the top-selling imported brands of “extra virgin” olive oil sold in the United States and purchased at retail locations throughout California often failed the IOC’s sensory standards for extra virgin olive oil. Sensory analysis showed that these failed samples had objectionable descriptors such as rancid and fusty. Sensory analysis is a sensitive tool to analyze olive oil quality and is an essential component of the IOC olive oil standards, but sensory analysis should be supported by gas chromatographic analyses and other analytical methods. It is essential to support sensory evaluations by chemical tests for volatile compounds that are known to be produced by lipid oxidation.

Our chemical tests indicate that the samples usually pass the IOC’s chemical tests even when those samples failed two IOC-accredited sensory panels. Chemical confirmation of the negative sensory results were strongest with the German/Australian DAGs and PPP tests, followed by IOC tests for UV absorption. The IOC and USDA standards would be more effective in assessing and enforcing olive oil quality by including the German/Australian DAGs and PPP standards.

Our testing indicated that the samples failed extra virgin olive oil standards for reasons that include one or more of the following: (a) oxidation by exposure to elevated temperatures, light, and/or aging; (b) adulteration with cheaper refined olive oil; and © poor quality oil made from damaged and overripe olives, processing flaws, and/or improper oil storage."

I believe the term ‘fake’ used in the article is possible not correct and is sensationalist. Possibly the term used should have been ‘failed’ standard regimes for extra virgin olive oils. The UCDOC has also provided reasons why some of the oils failed, and only one was because they believe the extra virgin olive oils had been mix with cheaper refined olive oils. Using the term ‘fake’ may lead readers to think that oils other than olive oils being used for such mixing. This appears not to be the case.

Other reasons for failing include inappropriate storage, handling of the extra virgin olive oils or use of lower grade of olives in pressing.

Having read the previous assessment carried out by Choice, Choice’s findings possibly were not dissimilar to those of the UCDOC.

It will be interesting to see if the assessment currently being conducted by Choice has shown any improvements since the last assessment.


Still if an oil is sold as 100% Virgin Olive Oil (and possibly with the added cost of a premium brand and labelling of quality) and has been cut with an inferior Olive Oil then perhaps it is a fake for those issues/reasons…failed also works but saying it is fake perhaps engenders a stronger negative response to the product and hopefully causes the producers to either change habits or remove themselves from the market.


It is definitely a part of the Uni of Calif. Davis campus. A link to the Agricultural arm of the Uni can be found here: and the Olive Center (US spelling :slight_smile: ) is part of that through the Robert Mondavi Institute (

A list of a few reports can be found here:

A listing of their projects here:

A statement of who they are:

Also the authors of the report are listed in the report but for ease of review I have copied that section:


Dr. Edwin N. Frankel, Scientific Advisor.
Dr. Frankel is among the world’s leading authorities on lipid oxidation. A former adjunct professor at the UC Davis Department of Food Science and Technology, he ranked in 2003-04 as the world’s most-cited author of agricultural research by the Institute for Scientific Information. Recently he has authored “Chemistry of Extra Virgin Olive Oil: Adulteration, Oxidative Stability, and Antioxidants,” Journal of Agricultural and Food Chemistry,
2010, 58, 5991-6006 and “Nutritional and Biological Properties of Extra Virgin Olive Oil,” Journal of Agricultural and Food Chemistry, 2011, 59, 785-792.

Dr. Rodney J. Mailer, Co-Investigator.
Dr. Mailer has been involved in olive research since 1996, and is the former principal research scientist and now a research fellow and adjunct professor at the Australian Oils Research Laboratory in Wagga Wagga, NSW. He headed the laboratory’s edible oil research program, which plays a leading role in national olive industry research, and is the Australian representative on the International Standards Organization (ISO) for Fats and Oils.

Dr. Selina C. Wang, Co-Investigator.
Dr. Wang received her Ph.D. in Chemistry from UC Davis in 2008. She has since lectured for the UC Davis Department of Food Science and Technology and is a research associate at the UC Davis Olive Oil Chemistry Laboratory, managing the analyses conducted in the laboratory.

Dr. Charles F. Shoemaker, Co-Investigator.
Dr. Shoemaker is the co-chairman of the UC Davis Olive Center and a professor in the UC Davis Department of Food Science and Technology. He super vises the UC Davis Olive Oil Chemistry Laboratory.
Dr. Shoemaker is a specialist in food emulsions, micelles, microemulsions, and food separations.

Dr. Jean-Xavier Guinard, Co-Investigator.
Dr. Guinard is a sensory scientist at the UC Davis Department of Food Science and Technology. He is the supervisor of the UC Davis Olive Oil Taste Panel.
Recently he has co-authored “How do consumer hedonic ratings for extra virgin olive oil relate to the quality ratings by experts and descriptive analysis ratings?” Food Quality and Preference 2011, 22(2): 213-225

Dan Flynn, Consultant.
Mr. Flynn is the executive director of the UC Davis Olive Center, the only center of its kind in North America. He leads the center’s efforts to promote research and education for table olive and olive oil growers and processors.

Nicole Sturzenberger, Consultant.
Ms. Sturzenberger is the assistant director of the UC Davis Olive Center.
Among other duties, she manages and helps lead the UC Davis Olive Oil Taste Panel.

We are grateful to Corto Olive, California Olive Ranch, and the California Olive Oil Council for their financial support
of this research. We value the leadership of Dr. Richard Cantrill, technical director of the American Oil Chemists’ Society (AOCS); the advice of the AOCS Expert Panel on Olive Oil (particularly Bruce Golino, member of the board of directors of the California Olive Oil Council and Paul Miller, president of the Australian Olive Association) and the expertise of Leandro Ravetti, senior horticulturalist and olive specialist at Modern Olives in Australia.

The authors thank the UC Davis Olive Oil Taste Panel, the Australian Olive Oil Sensory Panel, Dr. Mike Clegg
(laboratory technician); Theresa Leung, Angelina Sansone, Hanjiang Zhu and Yi Zhou (graduate students); Jenna
Zhang and Christopher Lam (undergraduate students); and other students for assisting in this project


Don’t disagree that ‘fake’ could be used where non-virgin oil was substituted, and it was proven to be the case. The UCDOC didn’t prove this was the case but speculated that it could be one of the reasons why a particular oil failed the test. It is plausible that shipping olive oil around the world, it may be inadvertently subject to the other conditions they outlined.

It is also plausible that the oils that failed the tests left the processing facilities as extra virgin olive oil and due to actions outside their control, caused the oils to fail. The manufacturers might be quite upset of the claims of being ‘fake’ on and on social media.

Don’t know whether the above is true, but the term ‘fake’ was not used by UCDOC and seems a little like trial by media.

It would be interesting if Choice would use the term ‘fake’ under similar circumstances.


It just goes to show that any research into Olive Oil (Oyl) should be done carefully … sorry, couldn’t resist :slight_smile:


Thanks for the detail on the Olive Centre and researchers. One thing that does stand out is
:[quote=“grahroll, post:28, topic:14705”]
We are grateful to Corto Olive, California Olive Ranch, and the California Olive Oil Council for their financial support of this research.[/quote]

Referring to @AliceRichard’s post about artificial sweeteners:

This olive oil industry support makes me question whether there are similar inherent biases in this olive oil research. This time to show that the American olive oil is superior, even if the foreign stuff passes the test.


That is always going to be the case because who funds research of anything? It is vested interests pro and con, industry hoping for a golden bank deposit without class actions for ‘bad outcomes’, donors (ie Choice members, foundations, etc), or taxpayers. There is a limit to what can get funded. Public good organisations like Choice are as impartial as it gets, but their coverage is necessarily budget constrained. So many things to investigate with so few resources.

The better question is not the general case where there is well founded suspicion, but whether there is evidence any particular study has scientific bias during peer reviews. That could be a prime area for academia to step in with ‘student power’.


I agree with both posts, the need for questioning the result is always there regardless of how it was funded. Any paper/report should be subject to the review of the evidence and results. In the Olive Center’s case I am not sure how many other institutions and researchers would actually be involved in similar science and thus it may limit the ability to get enough peer review of reports. However the results do closely resemble Choice’s past review and I guess that does strengthen their case and helps point to perhaps a “good” report.

One of Olive Center’s stated aims are to improve the Calif. Olive Oil industry and I would think if they produced “dodgy” reports this would hamper rather than enhance that prospect. Still a touch of doubt to a reports veracity is not harmful unless it overrides the consensus evidence and results as has happened in some other areas of science.

The Olive Center does seem to have some credibility in regards to their association with IOC who are not a US institution but are rather a body that is headquartered in Spain.

Singnatories to the IOC agreement can be seen in this pdf (please note this is a download link and you should always check the downloaded file by a virus scan before opening)


The University of California at Davis is the third largest university in the University of California system. It is world renowned for its research particularly in agriculture. While scepticism is a good thing to have when defending consumers it is hard to believe that the university would put its reputation at risk by using false or misleading results.

I remember visiting the Mondavi Center and learning for the first time that I was probably buying oil that was actually rancid when purchasing many brands from off the shelf of the supermarket. If memory serves they had hosted an Australian Fulbright scholar. While Australians are somewhat expert at using phyto-sanitary rules as trade barriers it does not seem unreasonable to believe that reputable olive oil producers (as would any reputable primary producer) would want some way to distinguish their products from the run of the mill alternatives.


As a counterpoint Australia does not have the full range of animal or plant diseases common in other parts of the world. If that is a trade barrier I happily and willingly subscribe to it, accepting bits of the rules can be over the top.


We’ve just released our EVOO review. Find the best olive oil, and see which ones to avoid.


Time to change brands that I use back to Cobram …


We’ved use Squeaky Gate oil and I was surprised about the reasons it was rejected, perhaps a bad sample?

I had a look in the pantry and found we still have some, so tasted it again and it was perfectly good, smooth, full of flavour and with a slight peppery aftertaste. Certainly no “fusty/muddy sediment, musty, rancid [or] winey-vinegary flavours”!


I’ll have to defer to @rclemons on this one @gordon. To my understanding, each oil that failed tests underwent a variety of further testing - new bottles from the same batch and different batches as well.

This from article is relevant to Squeaky Gate:

The panel detected the same defect in a second bottle of the same batch (bought from a different store in case the first bottle had been affected by poor storage conditions at the retail level), while the third bottle tested (from a different batch) was defect-free. Both samples from the first batch also had the highest FFA percentages in our test, indicating potential damage to the fruit at the time of crushing.


I was feeling badly about recommending Squeaky Gate Bold to @vax2000 after reading the test, but you highlight the evidence is they may have had a bad product batch. That could reflect their processing or could have been a once off. It would be interesting for a follow-up sampling a number of batches to see if there was an aberration or they are an inconsistent product.


An interesting article regarding the provenance of Australian olive oils.


A very interesting article regarding olive oil production at Cobram Estates.

I was amazed by the harvester. I thought that they still hand picked olives.