Acidity in Olive Oil: What It Really Means
Acidity in olive oil isn’t about taste—it’s about quality. Learn how it’s measured, why it matters, and what a low level really tells you.
Acidity is the most quoted number in olive oil and the most misunderstood. It has nothing to do with how sharp or sour the oil tastes. You cannot detect it on the palate at all.
What is actually being measured
Free acidity is the percentage of fatty acids that have broken away from their original structure, expressed as oleic acid. It is measured in a laboratory, not by tasting, and it rises when the fruit has been damaged, left sitting, attacked by olive fly, or pressed too long after picking.
Why a low number is a proxy for care
Because acidity tracks handling, it works as a summary of everything that happened before the mill. Hand-picking into sacks instead of shaking onto the ground, and pressing within hours instead of days, are what keep it low. A low number is evidence of a process, not of a variety.
The thresholds worth knowing
To be sold as extra virgin, an oil must test at or below 0.8% free acidity. That is a legal ceiling, not a target. Our oils sit at 0.20% for BIO Crete and 0.30% for Crete and Lesvos — well under half the permitted maximum.
Acidity is not the whole picture
A low acidity oil can still be old or dull. That is why we publish K232 and K270 values, which indicate oxidation, alongside polyphenol content and the harvest and bottling dates. Read them together and the bottle stops being a guess.
Acidity tells you how the fruit was treated. Polyphenols tell you what survived. Dates tell you how long ago. Ask for all three.
Our lowest acidity oil
BIO Crete tests at 0.20% free acidity — a quarter of the extra virgin limit.
