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​Testing parameters explained​

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Ceritas Score:

Our overall rating. It blends each oil's total biophenols, value for money (based off largest available size bottle at or less than one litre), and laboratory results into a single percentage. The categories used to generate this score are benchmarked against other oils on this list. The closer to 100%, the stronger the all-round package — higher is better. All oils on this list were selcted as they were felt to represent premium products. A low score does NOT mean that this oil is a bad oil, it simply represents a numeric value of how its categories relate to the benchmarks. Categories selcted include: 1 - biophenols HPLC, 2 - combined NIR results, 3 - value for money. 

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Biophenols (HPLC):

Biophenols (polyphenols) are the natural antioxidants in olive oil, linked to its health benefits and to that peppery, bitter freshness. This figure is measured by HPLC — the laboratory gold-standard method — and reported in mg/kg. A higher number generally means a fresher, more robust, more healthful oil.

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Near-Infrared Spectroscopy (NIR)

Extra Virgin is the highest grade of olive oil — pressed from fresh olives by purely mechanical means, never refined, and held to strict chemical and sensory limits set by the International Olive Council. The lab results  below (excluding polyphenol content) define part of the laboratory assessment of extra virgin status. 

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Free Fatty Acid (FFA) content (NIR)

A core freshness marker showing how much the oil's fats have broken down, given as % oleic acid. Lower is better — Extra Virgin must be ≤ 0.8%. A high value may indicate damaged fruit or degradation during processing.

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Peroxide value (NIR)

Measures primary oxidation — how far the oil has started to turn rancid through exposure to oxygen, light or heat. Reported in mEq O₂/kg, with an Extra Virgin limit of ≤ 20. Lower means fresher, better-stored oil.

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Delta-K, specific extinction (K232) and absorbance at 268nm (K268) (NIR)

UV absorbance readings that reveal oxidation and whether an oil has been refined or blended with lower-grade oil. Each has a strict Extra Virgin limit (K232 ≤ 2.50, K268 ≤ 0.22, Delta-K ≤ 0.01). Passing all three signals a genuine, unadulterated oil — lower is better.

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Polyphenol content by NIR

A second reading of the oil's polyphenols, taken by near-infrared analysis instead of HPLC. NIR is fast and non-destructive — it predicts polyphenol levels from the oil's infrared "fingerprint," whereas HPLC physically separates and counts each compound. The two figures won't match exactly: treat the HPLC number as the definitive measure and this NIR figure as a supporting cross-check.​

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Testing process

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​We researched hundreds of Australian groves for suitable products. Inclusion criteria included: 2026 harvest dates, early harvest timing, available between April and June. Products were purchased anonymously with no forewarning or involvement of suppliers.

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Testing was performed with the International Olive Council (IOC) recognised method for accurate biophenol quantification - high performance liquid chromatography (HPLC) at the Modern Olives laboratory in Australia. Testing of NIR was performed partially at the Wagga Labs, and partially at the Modern Olives labs. See our information section for more on this. 

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Why Australian and not all international oils? At Ceritas, we value consistency and control of variables to achieve results. Australia's high agricultural and food health and safety standards ensure a certain level of quality is achieved before testing has even begun. ​Purchasing Australian supports local industry development. Australia's early harvest season is currently underway, meaning that what you purchase now is at peak freshness. 

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Please note, that the information displayed in the tables above is only representative of the individual olive oils that were received and tested by Ceritas. They are not definitively representative of the entire batch as a whole. 

 

Want your brand tested?
If your brand is not featured here but think that it fits the bill, we can anonymously purchase, test and rank your product. We only ask you pay us for the cost of testing and purchase. Contact us via email - info@ceritas.com.au or by the website form. 

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International Olive Council. Trade standard applying to olive oils and olive pomace oils. COI/T.15/NC No 3/Rev. 21. Madrid: International Olive Council; 2025 [cited 2026 Jun 10]. Available from: https://www.internationaloliveoil.org/wp-content/uploads/2025/07/TRADE-STANDARD-REV-21_EN.pdf