Frequently asked questions

What counts as a high-polyphenol olive oil?

There is no legal definition; specialist labs and curators commonly use around 500–600 mg/kg total polyphenols as an informal bar. Ordinary extra virgin olive oil typically measures 100–300 mg/kg; oils above 1,000 mg/kg are often called ultra-high phenolic. We rank every lab-verified oil we track by its raw value, so you can apply whatever bar you prefer.

Why do you show the lab method next to every value?

Because values from different methods are not directly comparable. Folin-Ciocalteu typically reads higher than HPLC or qNMR for the same oil. We rank by the raw value the lab reported and display the method, rather than applying a hidden conversion factor you can't verify.

What does the EU health claim for olive oil polyphenols say?

Under EU Regulation 432/2012, olive oil polyphenols contribute to the protection of blood lipids from oxidative stress. The claim applies only to oils providing at least 5 mg of hydroxytyrosol and its derivatives per 20 g of olive oil, consumed daily. It is not a claim about treating or preventing any disease.

Does a higher polyphenol number always mean a better oil?

No. Polyphenol content declines with time and poor storage, so harvest date and freshness chemistry (acidity, peroxide value) matter, and very high-phenolic oils taste intensely bitter and peppery, which not everyone wants. That's why our master ranking (raw mg/kg) and our editorial 'best overall' score are kept separate.

How do I verify a producer's polyphenol claim?

Ask for the lab report (certificate of analysis) and check four things: the testing laboratory's name, the method (qNMR, HPLC, or Folin-Ciocalteu), the harvest or batch the sample came from, and the date of analysis. A claim with no report, no method, and no harvest year is a marketing number, not a lab value.

Why is an oil missing from your rankings?

We haven't found sufficient lab evidence for it yet, or it simply isn't in our database. You can suggest any oil with a lab report via our submission page — there is no fee, and brands cannot pay to be listed.

Do polyphenol levels change between harvests?

Yes, significantly. The same oil can vary by hundreds of mg/kg between harvest years depending on cultivar, harvest timing, weather, and processing. We re-verify ranked entries quarterly and tie every value to its harvest year.