Organic Olive Oil Acidity

When people try extra virgin olive oil, they sometimes tell me it’s very acidic. What they probably feel is bitterness, some pungency in the throat, maybe some astringency, and they call these sensations “acidity”. It wouldn’t be incorrect if it wasn’t for the fact that experts decided to call “olive oil acidity” a chemical quality of olive oil which is not perceivable with senses.

Acidity can only be detected with lab tests but it’s also true that high acidity is the consequence of fermentation and oxidation that affect, when occurring, the organoleptic qualities too. So it is safe to infer that an oil with organoleptic defects will also have high acidity.

Olive oil acidity is the percentage of free oleic acid, not bound to other chemical components of the olive oil. The higher it is, the lower the quality of the olive oil. In order to be classified as “extra virgin”, an olive oil must have an acidity level below 0.8%. Otherwise it will be classified as “virgin” (between 0.8% and 2%).

The best EVOOs have an acidity lower than 0.4% and some boast an acidity lower than 0.2%. The same is for organic olive oil. An organic olive oil doesn’t necessarily have a lower acidity than a conventional. Let’s see why.

Parameters affecting the olive oil acidity.

Olive oil acidity is not the only parameter to evaluate the quality of an EVOO but it is a fundamental one. So how to obtain a low acidity percentage?
  • Protect the olive trees and the olives from infestation. This is a challenge that organic farmers have to face in a different and sustainable way.
  • Protect the olive skin. Damaged skin causes an increase of acidity.
  • Harvest early. Farmers need to find the sweet spot to harvest olives before they ripe completely but not too early otherwise the yield would be too low and the flavour too bitter. This goes against the old practice of harvesting late in order to increase the yield to the detriment of quality.
  • Transport the olives with extra care not to damage them, keep the temperature as low as possible and follow best practices to avoid fermentation.
  • Once at the mill, start the extraction process as soon as possible (within a few hours from the harvest). Create an environment with ideal temperature and away from light for the waiting time.
  • Keep the extraction temperature as low as possible, always under 27°C to classify the oil as “cold pressed / extracted”. Specially the phase called kneading has to be shorter than 60 minutes.
  • Decant the oil as soon as possible after the extraction process.
  • Stock the oil properly.
  • Filter the oil. Unfiltered maintains its organoleptic quality and chemical profile for a shorter time.
All the procedures to follow in order to obtain the highest quality product possible, are the same for organic and conventional EVOOs. However organic olive oil has to undergo a series of laboratory tests to verify the absence of hundreds of pesticides commonly used in conventional agriculture.

So, if you have to choose between an organic olive oil and a conventional, both with a low level of acidity but in one case there is a remarkable reduction of the risk of contamination, environmental pollution and disrespect of local communities, which one would you choose?

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