0.2 percent, 0.4 percent, or 0.8 percent: Anyone who takes a deeper interest in premium olive oil will sooner or later encounter the so-called acidity level.
This value is one of the most important chemical analysis parameters for olive oil. At the same time, it is perhaps the most frequently misunderstood laboratory value.
An olive oil with 0.2 percent acidity does not automatically taste less acidic than one with 0.5 percent. Nor does an exceptionally low value prove extraordinary quality on its own.
So, what is actually being measured? What limit values apply to extra virgin olive oil? Why can refined olive oil also have a very low acidity level? And what role do the peroxide value, K232, K270, polyphenols, and sensory testing play?
In this Green Agora guide, we explain the acidity of olive oil step by step and demonstrate, using selected laboratory values from our range, how this parameter can be sensibly interpreted.
What does acidity mean in olive oil?
The term "acidity" is initially somewhat misleading for consumers.
It does not refer to how sour an olive oil tastes in the mouth.
In the laboratory, the proportion of free fatty acids is determined. In olive oil, the result is usually calculated and expressed as a percentage of free fatty acids in terms of oleic acid.
Simply put, an acidity level of 0.20 percent means that the measured amount of free fatty acids corresponds mathematically to 0.20 grams of oleic acid per 100 grams of olive oil.
As such, it is a chemical analysis value and not a flavor description.
Free fatty acids are created by the breakdown of triglycerides
The majority of fatty acids in intact olive oil are bound in triglycerides.
When these bonds are broken, free fatty acids are formed.
This process can begin even before the olive oil is produced.
The quality of the harvested olives is therefore particularly important.
Damaged fruit, long waiting times before processing, or unfavorable conditions between the harvest and the olive mill can promote the development of free fatty acids.
A low acidity level can therefore be an indication that healthy olives were handled carefully and processed promptly.
However, it is only one part of the quality assessment.
Does olive oil with a higher acidity level taste more sour?
No.
The acidity of olive oil should not be confused with the acidic taste of foods like lemon juice or vinegar.
Free fatty acids are not reliably detected through an acidic taste.
A consumer therefore cannot determine whether an olive oil has, for example, 0.20 or 0.50 percent free acidity simply by tasting it.
A chemical analysis is necessary for a reliable determination.
How is the acidity of olive oil measured in the laboratory?
Standardized laboratory procedures exist for the determination of free fatty acids.
The International Olive Council, for instance, uses method COI/T.20/Doc. No 34 to determine free fatty acids.
The basic principle is titration.
1. A defined olive oil sample is prepared
The laboratory takes an exact, measured quantity of the sample to be analyzed.
2. The olive oil is dissolved in a suitable solvent
This makes the free fatty acids accessible for subsequent determination.
3. The free fatty acids are titrated
The sample is titrated with a standardized alkaline solution.
From the amount required for this, it can be calculated how many free fatty acids are present in the sample.
4. The result is expressed as oleic acid
For olive oil, the result is usually expressed as a percentage of free fatty acids in terms of oleic acid.
This produces a lab value of, for example, 0.14 percent, 0.24 percent, or 0.47 percent.
Learn more about the analysis of other components in our article How is the polyphenol content in olive oil measured.
The most important EU limit value | 0.8 percent for extra virgin olive oil
The European Union establishes specific limit values for various categories of olive oil.
According to Delegated Regulation (EU) 2022/2104, the following maximum values for acidity apply, among others:
- Extra virgin olive oil: maximum 0.80 percent
- Virgin olive oil: maximum 2.0 percent
- Refined olive oil: maximum 0.30 percent
- Olive oil composed of refined olive oil and virgin olive oil: maximum 1.00 percent
What is particularly important for consumers is:
An acidity level below 0.8 percent is not enough on its own for an olive oil to be classified as extra virgin.
The extra virgin olive oil category requires additional chemical and sensory criteria.
These include, among other things, requirements regarding the peroxide value, UV absorption, and other analytical parameters.
Sensory testing is also crucial. For extra virgin olive oil, the EU requires, among other things, a median defect of 0 and perceptible fruitiness.
Learn more about the quality grade in our guide Extra virgin olive oil | What the highest quality grade means.
Why an extremely low acidity level does not automatically mean better quality
This is one of the most common misconceptions when buying olive oil.
0.10 percent looks better on paper than 0.30 percent.
But it does not automatically follow that the first olive oil is of higher sensory quality.
A particularly good extra virgin olive oil can, for example, have an acidity of 0.30 percent while showing excellent sensory properties, low oxidation values, and an interesting phenolic composition.
Additionally, there is a crucial point:
Even refined olive oil is permitted by EU law to have a very low acidity level of at most 0.30 percent.
Nevertheless, this is not extra virgin olive oil.
This clearly shows why the acidity value should never be viewed in isolation.
What a low acidity level can actually indicate
For a virgin olive oil, a low content of free fatty acids can be a positive indicator.
It can suggest that the olives were processed in good condition and that no significant hydrolytic damage occurred between harvest and processing.
The following are particularly relevant:
- Health and integrity of the olives
- Care during harvest
- Damage during transport
- Time between harvest and processing
- Conditions before processing
- Hygiene and process management in the olive mill
Acidity is therefore a useful building block for assessing the quality of raw materials and processing.
However, it remains only one building block among several.
Does early harvest automatically mean lower acidity?
Not automatically.
Early harvest olive oils are produced from olives harvested relatively early in the ripening process.
They can possess distinct sensory properties and high levels of certain phenolic compounds.
However, the degree of ripeness alone does not determine the free acidity.
An early-harvested olive can still be damaged or stored under poor conditions.
Conversely, a more mature, healthy olive can deliver a very good acidity value if handled carefully.
The deciding factor is therefore the interplay of olive variety, state of the fruit, harvest, transport, and rapid processing.
Learn more about this topic at Early harvest olive oil | Understanding early harvest.
Does organic olive oil automatically have a higher acidity?
No.
One cannot infer from an organic certification that an olive oil must generally have a higher or lower acidity.
Organic primarily describes requirements for ecological production and control.
The content of free fatty acids, on the other hand, is significantly influenced by the condition of the olives and the conditions during harvest, transport, and processing.
An organic olive oil can therefore have a very low acidity value. Likewise, a conventionally produced olive oil can have a higher value, and vice versa.
Organic certification and acidity level should be viewed as different product properties.
Acidity and polyphenols are not the same
These two values are also frequently conflated.
Acidity describes free fatty acids.
Polyphenol content describes a group of naturally occurring phenolic compounds.
There is therefore no simple rule such as:
The lower the acidity, the higher the polyphenols.
A premium olive oil can simultaneously have a low acidity and a high polyphenol content. However, this does not mean that the two values are directly dependent on each other.
Olive variety, harvest time, processing, and storage affect different analytical parameters in different ways.
Learn more about polyphenols in our guide Polyphenols in olive oil | What the lab values mean.
Acidity and peroxide value | Two different pieces of information
Acidity and peroxide value also answer different questions.
Acidity provides information about free fatty acids.
The peroxide value, by contrast, captures products of primary oxidation.
An olive oil can therefore have a very low acidity level while still being conspicuous in other quality parameters.
This is exactly why the EU looks at multiple analytical parameters simultaneously when classifying olive oil.
For extra virgin olive oil, the EU maximum value for the peroxide value is currently 20 milliequivalents of oxygen per kilogram.
What do K232, K270, and Delta K mean?
The so-called UV parameters are also part of the chemical assessment of olive oil.
This involves examining how strongly the olive oil absorbs light at specific wavelengths.
These values can provide clues about oxidation processes and certain changes in the olive oil.
For extra virgin olive oil, the EU sets limit values for K232, K268, or K270 and Delta K, among others.
Here too, the rule is:
None of these values should be used alone as a complete quality judgment.
Sensory testing is part of classifying extra virgin olive oil
Olive oil is one of those foodstuffs where chemical lab values are not the only things that matter.
Sensory criteria are also relevant for classification as extra virgin olive oil.
Such an olive oil must be fruity and must not exhibit any perceptible sensory defect during the official sensory examination.
This is a major reason why Green Agora does not look only at lab numbers when assessing a premium olive oil.
Fruitiness, bitterness, pungency, and aroma also belong to the overall picture.
We explain more about this at How to recognize good olive oil.
Current EU limit values for extra virgin olive oil at a glance
For the extra virgin olive oil category, the current EU regulation covers several quality characteristics.
- Acidity: maximum 0.80 percent
- Peroxide value: maximum 20.0 milliequivalents of oxygen per kg
- K232: maximum 2.50
- K268 or K270: maximum 0.22
- Delta K: maximum 0.01
- Median of defects: 0
- Median of fruitiness: greater than 0
- Fatty acid ethyl esters: maximum 35 mg per kg
In addition, further requirements regarding composition and purity apply.
This overview clearly shows why the statement "0.2 percent acidity means top quality" is too simplistic.
An olive oil must be evaluated as a complete product.
Can the acidity level be advertised on the label?
Even in labeling, the acidity value is not a marketing parameter that can be isolated at will.
According to current EU regulations, the statement of the maximum acidity expected until the best-before date may only appear on the label in conjunction with other information.
This includes the expected maximum values for:
- Peroxide value
- Wax content
- UV absorption
This information must appear in the same field of vision and in equally sized characters.
The background is understandable: consumers should not judge quality solely on the basis of a particularly attractive-looking acidity figure.
Analytical values of selected Green Agora olive oils
In the laboratory analyses provided by Green Agora, the following acidity values can be found for selected premium olive oils.
The values each refer to the analyzed sample or batch. Olive oil is a natural product, and analytical values can vary between harvests and batches.
- Pamako Gold Bio: 0.24 percent
- Pamako Blend Bio: 0.24 percent
- Kouros of Zeus Early Harvest from Kalamon Olives: 0.14 percent
- Pathos Bio: 0.18 percent
- Di Morea Bio: 0.34 percent
- Voliotis Early Harvest: 0.19 percent
- Voliotis Bio: 0.30 percent
- Voliotis Extra: 0.30 percent
- Creta Eleon Bio: 0.30 percent
- Marmaro: 0.20 percent
- Mitira Bio: 0.47 percent
All analytical values listed here are below the EU maximum value of 0.80 percent for the parameter of free acidity in extra virgin olive oil.
However, this explicitly does not mean that the acidity value alone justifies the classification as extra virgin olive oil.
For that, the other prescribed chemical and sensory criteria must also be met.
What do the Green Agora values show in a direct comparison?
The numbers demonstrate well why a lab value can be interesting without automatically forming a ranking.
Kouros of Zeus Early Harvest, for example, shows an acidity value of 0.14 percent in the provided analysis.
Pathos Bio is at 0.18 percent, Marmaro at 0.20 percent, Pamako Gold Bio and Pamako Blend Bio each at 0.24 percent.
Mitira Bio is higher at 0.47 percent, yet still clearly within the EU limit value for extra virgin olive oil.
From these figures alone, it is not possible to deduce which of these olive oils tastes better.
That is precisely why further analytical values and, above all, sensory characteristics must be considered.
Pamako Gold Organic | 0.24 percent acidity and 2081 mg polyphenols per kg
Pamako Gold Organic demonstrates particularly well why several analysis parameters are interesting when viewed together.
The recorded acidity value is 0.24 percent.
The currently confirmed polyphenol value is 2081 mg polyphenols per kg.
Pamako Gold Organic is produced from Tsounati olives and comes from Crete.
This allows for a combined assessment of acidity, polyphenol profile, olive variety, origin, and sensory characteristics for this premium olive oil, among other things.
You can find out more about Pamako in our article Pamako | Laboratory values, certificates, and quality.
Kouros of Zeus Early Harvest | 0.14 percent acidity and 835 mg polyphenols per kg
Kouros of Zeus Early Harvest, made from Kalamon olives, shows an acidity value of 0.14 percent in the stored analysis.
The currently confirmed polyphenol value is 835 mg per kg.
The combination of the Kalamon olive, early harvest, and documented analysis values makes this premium olive oil particularly interesting for people who are more intensively engaged with different Greek olive varieties.
Discover Kouros of Zeus Early Harvest
Further information can be found under Kouros of Zeus | Laboratory analyses and quality.
Di Morea Organic | 0.34 percent acidity and 664 mg polyphenols per kg
Di Morea Organic shows an acidity level of 0.34 percent in the stored analysis.
The currently confirmed polyphenol value is 664 mg per kg.
This premium olive oil is made from Koroneiki olives and comes from Messenia in the Peloponnese.
The comparison shows here as well that an acidity value, together with polyphenols, olive variety, origin, and sensory profile, is significantly more meaningful than an isolated figure.
Find out more in our article Di Morea Organic premium olive oil from Messenia.
Marmaro | 0.20 percent acidity and 528 mg polyphenols per kg
Marmaro shows an acidity value of 0.20 percent in the stored analysis.
The currently confirmed polyphenol value is 528 mg per kg.
This premium olive oil comes from Chalkidiki and is made from Hondroelia olives.
You can find out more about the origin and flavor profile under Marmaro premium olive oil from Chalkidiki.
Mitira Organic | Why 0.47 percent is not a bad value
Mitira Organic provides a good example of why consumers should not read acidity values like a leaderboard.
The stored acidity value is 0.47 percent.
This means Mitira Organic is higher than some other premium olive oils in our overview, while at the same time being well below the EU maximum of 0.80 percent for extra virgin olive oil.
The currently confirmed polyphenol value is 426 mg per kg.
Mitira Organic is made from the Kolovi and Adramitiani olive varieties typical of Lesbos.
The number 0.47 does not, therefore, mean that the olive oil must be qualitatively inferior to a product with 0.20 percent.
For a sensible evaluation, the overall picture must always be considered.
Find out more under Mitira Organic premium olive oil from the island of Lesbos.
Can the acidity level change during storage?
A laboratory value always refers to the sample examined at the time of analysis.
Olive oil does not remain chemically completely unchanged during storage.
How individual parameters develop depends, among other things, on composition, packaging, temperature, light, oxygen, and storage duration.
Oxidation processes are of particular importance for storage quality.
Therefore, we recommend keeping premium olive oil in a dark place, avoiding unnecessary heat, and ensuring it is well-sealed after opening.
Find out more under Storing olive oil correctly.
Can you test the acidity of olive oil at home?
For consumers, there is no reliable simple taste or kitchen test that can, for example, distinguish between 0.20 and 0.40 percent free acidity.
A reliable determination is made analytically.
Those interested in the exact value of a premium olive oil should therefore consult a laboratory report or the analysis data provided by the manufacturer.
What is more important | Acidity, polyphenols, or sensory characteristics?
The wrong question would be to declare just one of these values the winner.
With high-quality premium olive oil, we look at several levels simultaneously.
Acidity
It describes free fatty acids and provides information on the condition of the olives and the processing, among other things.
Polyphenols
They describe a group of natural phenolic compounds and can be examined analytically in a differentiated manner.
Peroxide value and UV values
They provide additional information on chemical quality and oxidation processes.
Sensory characteristics
Fruitiness, bitterness, pungency, harmony, and possible defects are essential in determining how an extra virgin olive oil is assessed and experienced.
Origin and olive variety
Koroneiki, Kalamon, Tsounati, Hondroelia, Kolovi, and other varieties bring out different characters.
Only this combination provides a truly meaningful picture.
Ayhan's personal assessment of acidity
If someone tells me an olive oil is excellent because it only has 0.15 percent acidity, this information is not enough for me.
I want to know which olive variety it was made from, where it comes from, how the olives were processed, what the other laboratory values look like, and, above all, how the olive oil affects the senses.
For me, a low acidity level is an interesting and positive analytical feature for an extra virgin olive oil.
However, I would never use it alone to create a quality ranking.
This can also be seen in our own products.
Kouros of Zeus Early Harvest shows 0.14 percent in the stored analysis, Mitira Organic 0.47 percent. Both values are well within the EU limit for extra virgin olive oil, even though they differ significantly from one another.
The more interesting question is therefore not just: How low is the acidity value?
The better question is: What do all the analytical values, the origin, and the taste tell us together about this olive oil?
Ayhan from Green Agora
You can find my personal product recommendations under Ayhan's olive oil favorites.
Frequently asked questions about the acidity of olive oil
What does an acidity level of 0.2 percent mean for olive oil?
The value describes the proportion of free fatty acids, calculated as oleic acid. Simply put, 0.2 percent corresponds to 0.2 grams of free fatty acids as oleic acid per 100 grams of olive oil.
How high can the acidity level be for extra virgin olive oil?
According to current EU regulations, the acidity level may not exceed 0.80 percent. In addition, numerous other chemical and sensory criteria must be met.
Is 0.2 percent acidity better than 0.5 percent?
Not automatically. Both values are within the limit for extra virgin olive oil. For a quality assessment, further analysis parameters and the sensory characteristics must be taken into account.
Does olive oil with higher acidity taste more acidic?
No. The laboratory value for free fatty acids is not to be equated with the sour taste of lemon juice or vinegar.
Is an acidity level of 0.8 percent still extra virgin olive oil?
Regarding the free acidity parameter, 0.8 percent is exactly at the EU maximum limit. However, the olive oil may only be classified as extra virgin if all other prescribed chemical and sensory requirements are also met.
Is an olive oil with 0.1 percent automatically of higher quality?
No. A very low acidity value alone is not complete proof of quality. Even refined olive oil can legally have a low acidity value.
Does organic olive oil have a higher acidity level?
No, not fundamentally. Organic certification and acidity levels describe different properties. The acidity value is significantly influenced by the condition and processing of the olives.
Does early harvest olive oil always have less acidity?
No. An early harvest can be part of quality-oriented production, but it does not in itself guarantee a specific acidity value.
Can I taste the acidity level?
No. A difference such as 0.20 versus 0.40 percent cannot be reliably determined via a sour taste. An analysis is required for this.
What is more important than a low acidity value?
It is not about a single feature. Peroxide value, UV values, other chemical parameters, sensory characteristics, origin, olive variety, processing, and available analysis values should be considered together.
May a manufacturer only advertise with a particularly low acidity value?
There are specific EU requirements for the labeling of olive oil. The indication of the expected maximum acidity on the label must not be done in isolation, but must be combined with other prescribed analytical values such as peroxide value, wax content, and UV absorption.
Further guides on olive oil quality and laboratory values
- How is the polyphenol content measured in olive oil
- Understanding polyphenols in olive oil
- How to recognize good olive oil
- Understanding extra virgin olive oil
- Understanding early harvest olive oil
- Pamako | Laboratory values, certificates, and quality
- Kouros of Zeus | Laboratory analyses and quality
- Storing olive oil correctly
Official sources and standards
For the legal classification of olive oil categories and limits, this article follows the current European regulation on marketing standards for olive oil.
EUR Lex | Delegated Regulation (EU) 2022/2104
Information on international standards and analysis procedures is provided by the International Olive Council.
International Olive Council | Standards and analytical methods
Discover premium olive oil with transparent analysis values
At Green Agora, we do not want to describe premium olive oil only with terms like high-quality or special.
Where corresponding analyses are available, verifiable laboratory values should provide additional guidance.
Nevertheless, for us, the overall picture consisting of origin, olive variety, processing, analysis, and taste remains decisive.
Do you have a question about a laboratory value or would you like to better classify a certain premium olive oil? Contact Green Agora directly.
WhatsApp: +49 175 9009341
Email: info@greenagora.de
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