Acidity vs. Polyphenols: Why You're Looking at the Wrong Number

Walk into any supermarket and you’ll see "0.3% acidity" displayed prominently on premium olive oil labels. It sounds scientific. It sounds reassuring.

It tells you almost nothing about quality.

What acidity actually measures

Free fatty acid (FFA) content is a measure of how much the oil has already degraded at a chemical level. Low acidity means the olives were healthy and processed quickly. It’s a baseline hygiene metric — necessary but not sufficient.

Think of it like this: a low-acidity oil is like a clean hotel room. It meets the minimum standard. But it doesn’t tell you about the view, the service, or the mattress quality.

What acidity doesn’t measure

• Polyphenol content (antioxidant density)
• Flavor complexity
• Harvest date or freshness
• Processing temperature
• Oxidation levels (peroxide value)

The real quality markers

The industry problem

Producers know consumers have been trained to look for low acidity. So they optimize for it. The result is a technically "extra virgin" oil with 0.2% acidity and 60 mg/kg of polyphenols.

A well-made early harvest oil might show 0.4% acidity and carry 450 mg/kg of polyphenols. By the label logic, the first one "wins." By any nutritional or flavor standard, it loses badly.

What to ask instead

• What is the polyphenol content per batch?
• What is the peroxide value at bottling?
• When was this oil harvested?

If a producer can’t answer these questions, the acidity number on the label is marketing, not quality assurance.

Explore our early harvest oils →