What does acidity mean in olive oil? A practical guide
What does acidity mean for olive oil? A practical guide
Anyone buying olive oil will sooner or later come across a value on the bottle: the acidity. Sometimes it says "max. 0.8%", sometimes "0.5%", sometimes nothing at all. What does this number mean — and why is it the most important quality indicator you should look for when buying?
In this guide, we explain what the acidity actually measures, which EU regulations apply, and what you should look for on your next purchase.
What does the acidity actually measure?
The acidity of olive oil refers to the proportion of free fatty acids in the oil, expressed as a percentage of oleic acid (acido oleico). It has nothing to do with the taste — a high acidity does not taste "more sour".
Instead, the acidity is a measure of the quality of the olives and the processing: the lower the value, the better the olives were treated.
Specifically, free fatty acids are formed when:
- Olives are damaged, overripe, or infested by pests
- Too much time passes between harvesting and pressing
- The olives were exposed to heat or oxygen during storage
- The pressing is carried out at temperatures that are too high
High-quality producers therefore press within a few hours of harvesting and work under controlled temperatures.
EU standards: Which value for which quality grade?
The EU regulates the classification of olive oil in Regulation (EU) No 1308/2013 and Implementing Regulation (EEC) No 2568/91. The acidity is the key criterion here:
| Quality grade | Maximum permitted acidity |
|---|---|
| Extra Virgin Olive Oil (highest grade) | 0.80 % |
| Virgin Olive Oil | 2.00 % |
| Olive Oil (Lampante oil, refined) | over 2.00 % — not for direct consumption |
| Olive Oil (blend of refined and virgin) | 1.00 % |
Only Extra Virgin Olive Oil (in Italian: olio extra vergine di oliva) meets the highest quality grade. Anything below that is either of limited use or must be industrially refined.
Important: The value "0.80%" is the upper limit for the "Extra Virgin" grade. Many high-quality oils are significantly below this — and this is precisely where the true quality shows.
Why lower acidity is better
The legal limit of 0.80% is generous. Premium producers are often at 0.3% to 0.5% — which indicates:
- Fresh olives: Rapid processing after harvest
- Gentle pressing: Low temperatures, controlled oxygen contact
- High-quality raw material: Healthy, undamaged fruit
- Better shelf life: Lower acidity correlates with higher stability against oxidation
An oil with an acidity of 0.5% is therefore not just "slightly better" than one with 0.8% — it is the expression of a completely different processing standard.
How is the acidity determined?
Measurement is performed in the laboratory by titration: a small oil sample is mixed with an alkali that neutralizes the free fatty acids. The percentage can be calculated from the quantity required.
Acidity is therefore an objective, chemically measurable value — not a sensory assessment or a marketing claim. Reputable producers state the value on the bottle or in the technical data sheet.
Acidity alone is not enough — what else counts
Acidity is the most important, but not the only, quality feature. Laboratories also check:
- Peroxide value (max. 20 meqO₂/kg for Extra Virgin): shows the degree of oxidation
- K232 and K270: Spectrophotometric values for assessing freshness
- Sensory analysis: Smell and taste by certified tasters
If a producer transparently discloses the acidity, that is a good sign — usually, the other values are solid as well.
DIVO Olive Oil: Acidity max. 0.50 %
DIVO Extra Virgin Olive Oil is produced at the facility of Basso Fedele & Figli S.r.l. in San Michele di Serino (Campania) — a family business since 1904. The acidity is a maximum of 0.50% and thus significantly below the EU limit of 0.80%.
This is achieved through:
- Cold pressing at below 27 °C
- Certified production (IFS Higher Level, BRCGS AA+, ISO 22000:2018)
- Continuous laboratory analysis of every batch
You can find out more about our production on our quality page. DIVO is available in 1L for the home kitchen, 3L for frequent cooks, and 5L for the catering industry.
Frequently asked questions
What is a good acidity for olive oil?
According to EU regulation, Extra Virgin Olive Oil may have a maximum acidity of 0.80%. Premium oils are usually between 0.3% and 0.5%. Values below 0.5% are considered a very high quality standard.
Does olive oil with high acidity taste sour?
No. Acidity refers to the chemical proportion of free fatty acids, not the sensory taste. A "sour" mouthfeel in olive oil is more indicative of oxidation or spoilage.
Is the acidity always on the bottle?
In the EU, the disclosure is not mandatory but is recommended. High-quality producers provide the value voluntarily — often in the technical data sheet. If the information is completely missing, it is a warning sign.
Which acidity is suitable for the catering industry?
For the professional kitchen, Extra Virgin Olive Oil with an acidity below 0.5% is recommended. These oils are more heat-stable, taste more consistent, and have a longer shelf life — which is crucial for large containers with a long consumption period.
Does the acidity decrease over time?
On the contrary — the acidity increases over time as olive oil ages naturally. That is why you should consume oil within 12–18 months of pressing and store it in a cool, dark, and airtight place.