by Dan Kollias, Kollias Olive Oil
What Is High-Polyphenol Olive Oil?
High-polyphenol olive oil is extra virgin olive oil with naturally elevated levels of phenolic compounds, antioxidants that contribute to bitterness, pepperiness, oxidative stability, and certain health benefits. Polyphenol levels are typically higher in early-harvest olive oil and decline as olives ripen.
What Are Polyphenols in Olive Oil?
Polyphenols are naturally occurring compounds found in many plant foods, including fruits, vegetables, tea, dark chocolate, and early-harvest extra virgin olive oil.
Polyphenols can act as antioxidants, helping to protect cells and lipids from oxidative stress. They are also associated with anti-inflammatory effects and have been studied for their potential role in cardiovascular and metabolic health.
Under European Union law, olive oils containing sufficient levels of certain phenolic compounds may carry the following authorized health claim: “Olive oil polyphenols contribute to the protection of blood lipids from oxidative stress.”
The claim may be used only for olive oil containing at least 5 mg of hydroxytyrosol and its derivatives per 20 g of olive oil, and the beneficial effect is obtained with a daily intake of 20 g of olive oil. (Commission Regulation (EU) No. 432/2012.)
Those same antioxidant properties also contribute to the stability of extra virgin olive oil. All else being equal—including filtration, storage conditions, and exposure to light and heat—olive oil with higher phenolic content will generally resist oxidation better than oil with lower phenolic content.
Why Does Early Harvest Olive Oil Have More Polyphenols?
Harvest timing is one of the major factors associated with phenolic content, although olive variety, climate, fruit condition, and processing methods also matter.
As olives mature and ripen, their phenolic content generally declines. For that reason, early-harvest olive oils often contain more polyphenols than oils made from fully ripened olives.
Can You Taste the Polyphenols in the Olive Oil?
Yes. Higher-polyphenol olive oils tend to have more pronounced bitterness and pungency—the peppery “kick” you may feel at the back of your throat.
We consider that a desirable characteristic. Our early-harvest olive oil has a robust flavor that distinguishes it from milder, more neutral oils. In Greece, this style of early-harvest olive oil is known as agourelaio, and it is prized for both its flavor and its freshness.
Is a Higher Polyphenol Count Always Better?
There is no single legal definition establishing a cutoff for when an olive oil may be called “high-polyphenol.” In practice, the term is generally used for extra virgin olive oils with relatively high concentrations of naturally occurring phenolic compounds.
Polyphenol levels vary from harvest to harvest and are influenced by olive variety, climate, ripeness, harvest timing, fruit condition, and processing. Early-harvest oils often contain more polyphenols, but the number should be viewed as one measure of quality—not as a stand-alone score.
There is also a relationship between polyphenol content and flavor. Very high-polyphenol oils are often more intensely bitter and pungent. Some consumers enjoy that intensity, while others may find those oils less versatile for everyday cooking.
Our olives are generally harvested and pressed from late October into early November. We choose that timing to balance freshness, phenolic content, aroma, bitterness, and pungency. The result is an olive oil with a distinctive early-harvest “kick” that is still enjoyable and versatile in the kitchen.
After all, we are selling food, not medicine. Enjoy it!
How many polyphenols are in Kollias Olive Oil?
Our 2025 Harvest 750 mL Single Source Early Harvest Extra Virgin Olive Oil tested at 377 mg/kg polyphenols, with acidity of 0.35%.
It is produced from Koroneiki olives grown on our family farm in Filiatra, Greece, and harvested and first cold-pressed during the early part of the olive season.
Want a broader look at olive oil quality?
See our guide to polyphenols, acidity, peroxide value, K232, K268 and ΔK, including Kollias laboratory results from the 2023, 2024 and 2025 harvests.
Explore our full collection of single-source early harvest Greek extra virgin olive oil.
