Quick Answers About Olive Oil Acidity
What does acidity mean in olive oil?
It's a laboratory measurement, not a sour taste. It tells you how much free fatty acid is present in the oil, something influenced by the condition of the olives and how they were handled.
What's a good acidity level?
Extra virgin olive oil can't go above 0.8%. Many extra virgin olive oils measure below that limit, but the number alone doesn't tell you which tastes better.
Is lower always better?
Not always. Both 0.2% and 0.4% meet the acidity requirement for extra virgin olive oil. Refined olive oil can measure even lower, so acidity alone doesn't prove quality.
Can I taste it?
No. The bitterness and pepper you taste come from other things in the olive. Only a lab test tells you the acidity.
How do I find a low acidity oil?
Buy extra virgin, look for a harvest date, and trust a printed acidity number only if it says when it was tested.
Does it change over time?
Yes, it can creep up as the oil ages. Keep the bottle closed and away from heat and light.
Is it related to acid reflux?
No, it's not the oil's pH. If you have reflux, ask your doctor what to eat.
Acidity is only one factor to consider when comparing olive oils. Read our complete guide to choosing extra virgin olive oil, or explore our 100% Italian Extra Virgin Olive Oil, 500 mL.
What Does Acidity Mean in Extra Virgin Olive Oil?
Acidity in extra virgin olive oil means free fatty acidity: the amount of free fatty acids present in the oil, expressed as a percentage of oleic acid.
It is measured in a laboratory. It is not the acidic taste you experience from foods such as lemons or vinegar.
Free acidity can be influenced by the condition of the olives and what happens before and during processing. Damaged fruit, delays before milling, and poor handling can contribute to higher free acidity.
For an olive oil to qualify as extra virgin, free acidity must not exceed 0.8 grams per 100 grams, expressed as oleic acid, together with the other chemical and sensory requirements for the category.
That last distinction matters: 0.8% is a classification limit, not a complete quality score. For the broader grade framework and how acidity fits within olive-oil classification, see how Italian olive oil is classified.
Does Lower Acidity Mean Better Extra Virgin Olive Oil?
If a producer reports very low acidity, that is useful information. The mistake is turning that one number into proof that the oil is automatically superior to every EVOO with a higher number.
Not automatically.
A lower free-acidity result can be a favorable analytical characteristic. An EVOO with 0.2% acidity has lower measured free acidity than one with 0.4%.
But that does not automatically mean the 0.2% oil is better in every other respect.
Both values are below the 0.8% maximum for extra virgin olive oil. And acidity alone does not tell you which oil has the better aroma, flavor, freshness, polyphenol concentration, sensory balance, or overall quality.
Think of acidity as one measurement in a larger picture.
This is one of several characteristics consumers commonly treat as proof of quality. For acidity misconceptions and other claims involving flavor, appearance, cooking, storage, and origin, see our guide to 24 common olive oil myths.
For an extra virgin olive oil that states its measured acidity, see our low acidity olive oil: Lumìa recorded 0.13% free acidity in its 2025 harvest analysis, alongside a peroxide value of 3.00 meq O₂/kg and 564 mg/kg of total polyphenols at milling.
Olive Oil Acidity Chart: Limits by Grade
An acidity chart, a table of the maximum free acidity allowed for each olive oil grade, shows where a measured number sits. The limits below are those published by the International Olive Council, expressed as grams of oleic acid per 100 grams of oil.
| Grade | Free acidity limit |
|---|---|
| Extra virgin olive oil | Not more than 0.8% |
| Virgin olive oil | Not more than 2.0% |
| Olive oil (blend of refined and virgin olive oils) | Not more than 1.0% |
| Refined olive oil | Not more than 0.3% |
| Lampante virgin olive oil | Above 3.3% under the IOC standard (above 2.0% under EU rules), or failing other chemical or sensory criteria for the edible virgin grades; not fit for consumption without refining |
Each grade must also meet other chemical and sensory criteria. Acidity alone does not decide which grade an oil belongs to.
Why a Low Number Is Not Proof of Quality
Refined olive oil, an oil treated with heat and processing to remove defects and flavor, is allowed a lower acidity limit than extra virgin olive oil, because refining strips out free fatty acids. A low acidity number therefore means most on an unrefined extra virgin olive oil, where it reflects the condition of the olives and the care taken at milling. The "light" and "extra light" olive oils sold in supermarkets are refined blends, not low-acidity extra virgin oils.
Can Olive Oil Acidity Change Over Time?
Yes. Free acidity can increase during storage as hydrolysis releases additional free fatty acids. Heat, light, and air can also contribute to other forms of oil deterioration, particularly oxidation. A laboratory result describes the oil when the sample was tested, usually soon after the harvest, not the oil in your bottle months later. That is why an acidity figure is most useful when it comes with a date, and why the bottle should be kept closed, away from the stove and sunlight.
Is Olive Oil Acidity the Same as Acid Reflux?
No. Free acidity, a measure of fatty-acid breakdown in the oil, is not the oil's pH and is not a measure of how acidic it is in the stomach. A low free acidity number cannot tell you whether an oil suits your digestion. If you have acid reflux or GERD, follow the advice of your doctor.
Can You Taste the Acidity in Olive Oil?
No — not directly.
This is probably the biggest source of confusion around olive oil acidity.
A peppery EVOO does not necessarily have lower acidity. A mild EVOO does not necessarily have higher acidity. And bitterness is not the taste of free fatty acids. For a closer explanation of these sensory characteristics, see Why Does Olive Oil Taste Peppery?
Those are different characteristics.
When tasting extra virgin olive oil, you may notice fruitiness, bitterness, and pungency. The exact profile varies considerably among oils.
Free acidity, on the other hand, requires analytical measurement.
So you cannot taste an olive oil and reliably say, “This tastes strong, so its acidity must be 0.2%.”
The laboratory number and the sensory experience answer different questions.
The Bottom Line
Olive oil acidity is useful information, but it is easy to give the number more meaning than it actually has.
For extra virgin olive oil, 0.8% is the maximum free-acidity limit. A lower result can provide additional information about the oil, but it does not create a separate grade of EVOO or automatically prove superior flavor, freshness, polyphenols, or overall quality.
Acidity tells you something important about an olive oil. It doesn't tell you everything about it. For the complete framework—including grade, freshness, origin, sensory characteristics, cooking, and storage—see our complete guide to extra virgin olive oil.
Have a question about olive oil acidity? Write to info@milantruffle.com.
