GUIDE
High-polyphenol
olive oil.
What polyphenols are, how they are measured, why levels vary so much between bottles, and how to tell a real figure from a marketing one.
Short answer: Polyphenols are natural compounds in olives that give extra virgin olive oil its bitterness and peppery kick. They are measured in milligrams per kilogram (mg/kg). Many oils sit around 100–250 mg/kg; oils above roughly 500 mg/kg are usually described as high-polyphenol. Early harvest, the olive variety, fast low-temperature milling and light-proof packaging all keep levels high.
What are olive oil polyphenols?
Polyphenols are a family of natural compounds that olives produce to protect themselves. In the oil, the best known are hydroxytyrosol, tyrosol, oleocanthal and oleacein. You can taste them: bitterness on the tongue and a peppery sting at the back of the throat usually mean a fresh, polyphenol-rich oil.
How are polyphenols measured?
Accredited laboratories measure polyphenols, usually by liquid chromatography (HPLC), and report the result in mg/kg of oil. Two things matter when you read a figure:
- When it was measured. Polyphenols fall over time. A figure taken at harvest can be far higher than what is left when you open the bottle months later.
- Whether it is a minimum. A guaranteed minimum until best-before is a stronger promise than a single test at harvest.
What makes an olive oil high in polyphenols?
- Early harvest: green, early-season olives contain more polyphenols, but yield less oil.
- Variety: Tuscan varieties such as Frantoio and Moraiolo are naturally rich in polyphenols.
- Speed to the mill: olives start to oxidise once picked. Milling within hours preserves more.
- Low temperature: kneading below 27°C (cold extraction) protects polyphenols that heat destroys.
- Storage and packaging: light, heat and oxygen break polyphenols down, so cans and dark glass help.
Yolioo polyphenol levels
| OIL | POLYPHENOLS | WHY |
|---|---|---|
| The Original | min. 500 mg/kg | Tuscan blend, milled within 6 hours at 22–24°C |
| First Yield | min. 600 mg/kg | Picked at the very start of the season, while olives are green |
| Lot 1, Chianti | 656 mg/kg | Early-harvest Frantoio from a single grove, where lower yields concentrate phenolics |
Every batch is analysed by an accredited laboratory, and our figures are guaranteed until the best-before date.
Questions
What counts as a high-polyphenol olive oil?
There is no legal definition. In practice, oils above roughly 500 mg/kg of total polyphenols are usually called high-polyphenol, while many standard extra virgin olive oils measure around 100–250 mg/kg.
How can I tell if my olive oil is high in polyphenols?
Look for a lab-tested figure in mg/kg, ideally a guaranteed minimum until best-before, plus a harvest date. On tasting, noticeable bitterness and a peppery throat sting are good signs.
Why is high-polyphenol olive oil bitter and peppery?
Polyphenols such as oleocanthal and oleacein cause the bitterness and the peppery sting. These are signs of a fresh, quality oil, not a defect.
Do polyphenols in olive oil decrease over time?
Yes. Polyphenols slowly break down after milling, faster with light, heat and air. That is why the date of the measurement and the packaging matter.
Does cooking destroy olive oil polyphenols?
Heat reduces some polyphenols, but a good share survives normal home cooking. For the most, use a high-polyphenol oil raw: drizzled on salads, soups, vegetables or bread.
Which Yolioo oil has the most polyphenols?
Lot 1, Chianti, our highest phenolic selection, with 656 mg/kg. First Yield follows with at least 600 mg/kg.