The legal limits below are those of the IOC trade standard and EU olive oil legislation. The “strong result” and “red flag” columns are practical buyer benchmarks, not legal thresholds.

Free acidity measures free fatty acids, expressed as a percentage of oleic acid. It rises when olives are bruised, diseased, or left too long between harvest and pressing. Extra virgin olive oil must be at or below 0.80%.

Acidity barely changes once oil is in the bottle. A low figure therefore reflects good fruit and fast milling, not freshness. A premium early harvest oil typically reads well under 0.40%. It is the most quoted number, but on its own it says the least.

Peroxide value measures the first products of oxidation, in milliequivalents of active oxygen per kilogram. The limit for extra virgin is 20. Freshly pressed, well-stored oil is usually well below 10.

Peroxide rises with exposure to air, light and heat. A value of 16 or 17 still passes, but it leaves little room for a long sea voyage and a year on a shelf. Read it alongside the analysis date.

K232 and K270 measure how the oil absorbs ultraviolet light at two wavelengths. Oxidation creates compounds that absorb at these points, so higher numbers mean older or more stressed oil.

• K232 tracks early oxidation. Extra virgin limit: 2.50.
• K270 tracks later oxidation and is also sensitive to refining. Extra virgin limit: 0.22.

These two values are the best predictors of shelf life on a COA. An oil with K232 near 1.7 has far more headroom than one at 2.4, even if both pass today.

ΔK compares absorbance around 270 nm to the values on either side of it. Refining produces compounds that create a sharp peak there. The extra virgin limit is 0.01, and authentic virgin oil normally reads 0.00.

Any ΔK above 0.01 is a serious warning. It points to refined olive oil or another refined oil in the blend.

Ethyl esters form when olives ferment before pressing, typically from damaged fruit or long storage in sacks. They are not natural components of fresh olive oil. The extra virgin limit is 35 mg/kg.

FAEE matters for two reasons. It can reveal “deodorised” oil, where defective oil is treated to remove off-flavours, because deodorising does not remove ethyl esters. It also rises slowly in storage, so an oil starting near the limit may fall out of grade before its best-before date. A Uruguayan shelf-life study found ethyl esters crossing the limit within about six months in one sample, while oxidation values stayed compliant.

The sensory panel is a legal test, not a tasting note. A trained panel scores the median of defects (Md) and the median of fruitiness (Mf). Extra virgin requires Md = 0 and Mf above 0. Virgin allows Md up to 3.5.

An oil can pass every chemical test and still fail here. A COA without a panel result cannot support an extra virgin claim on its own.

Purity tests answer a different question: is this genuinely olive oil, and only olive oil? Buyers rarely need to interpret every value, but they should check each one sits within its limit.

Limits are revised from time to time. Always check them against the current IOC trade standard or EU Delegated Regulation (EU) 2022/2104, not an older document.

Free acidity measures free fatty acids, expressed as a percentage of oleic acid. It rises when olives are bruised, diseased, or left too long between harvest and pressing. Extra virgin olive oil must be at or below 0.80%.

Acidity barely changes once oil is in the bottle. A low figure therefore reflects good fruit and fast milling, not freshness. A premium early harvest oil typically reads well under 0.40%. It is the most quoted number, but on its own it says the least.

Peroxide value measures the first products of oxidation, in milliequivalents of active oxygen per kilogram. The limit for extra virgin is 20. Freshly pressed, well-stored oil is usually well below 10.

Peroxide rises with exposure to air, light and heat. A value of 16 or 17 still passes, but it leaves little room for a long sea voyage and a year on a shelf. Read it alongside the analysis date.

K232 and K270 measure how the oil absorbs ultraviolet light at two wavelengths. Oxidation creates compounds that absorb at these points, so higher numbers mean older or more stressed oil.

• K232 tracks early oxidation. Extra virgin limit: 2.50.
• K270 tracks later oxidation and is also sensitive to refining. Extra virgin limit: 0.22.

These two values are the best predictors of shelf life on a COA. An oil with K232 near 1.7 has far more headroom than one at 2.4, even if both pass today.

ΔK compares absorbance around 270 nm to the values on either side of it. Refining produces compounds that create a sharp peak there. The extra virgin limit is 0.01, and authentic virgin oil normally reads 0.00.

Any ΔK above 0.01 is a serious warning. It points to refined olive oil or another refined oil in the blend.

Ethyl esters form when olives ferment before pressing, typically from damaged fruit or long storage in sacks. They are not natural components of fresh olive oil. The extra virgin limit is 35 mg/kg.

FAEE matters for two reasons. It can reveal “deodorised” oil, where defective oil is treated to remove off-flavours, because deodorising does not remove ethyl esters. It also rises slowly in storage, so an oil starting near the limit may fall out of grade before its best-before date. A Uruguayan shelf-life study found ethyl esters crossing the limit within about six months in one sample, while oxidation values stayed compliant.

The sensory panel is a legal test, not a tasting note. A trained panel scores the median of defects (Md) and the median of fruitiness (Mf). Extra virgin requires Md = 0 and Mf above 0. Virgin allows Md up to 3.5.

An oil can pass every chemical test and still fail here. A COA without a panel result cannot support an extra virgin claim on its own.

Below are the results from one of our early harvest extra virgin batches, with the lot and customer details removed.

The useful reading is not “it passes” but “by how much.” Every quality value sits well inside its limit. That headroom is what keeps the oil in grade through a four-week voyage and months on a retailer’s shelf.

Ask for a pre-shipment sample alongside its COA, and keep a sealed counter-sample from the same lot. Write the target specification into the contract, parameter by parameter. Then test on arrival at an independent laboratory, especially for a first order.

A serious supplier welcomes this. It is how long-term bulk and private label programmes are built.

The COA is separate from the health or free sale certificate issued by the Turkish Ministry of Agriculture and Forestry. Both travel with an export shipment, but only the COA describes the oil’s chemistry. See the full shipping document set on our private label and bulk supply page.

Polyphenol content is not a grade parameter, so most standard COAs omit it. If you plan a health claim in the EU, request a separate polyphenol analysis. Under Regulation (EU) No 432/2012, the olive polyphenol claim requires at least 5 mg of hydroxytyrosol and its derivatives per 20 g of oil.

A COA also does not tell you how the oil will taste to your customers. Ask for samples of the batch itself, not a reference oil.