The industry needs major TLC.
According to the UC Davis Olive Center, nearly 70% of imported olive oil samples failed to meet minimum sensory standards for extra-virgin olive oil, and had defects ranging from rancidity to adulteration with cheaper refined oils.
SOURCES
UC Davis Report:
Evaluation of Extra Virgin Olive Oil Sold in California
UC Davis
Report: Tests Indicate that Imported Extra Virgin Olive Oil Often Fails International and USDA Standards
Adulterated olive oils can contain a blend of inferior quality vegetable oils like soybean oil, sunflower oil, palm oil or canola oil.
Olive oil can go bad during a variety of commercial production processes.
i. Olive oil becomes moldy when the olives have been crushed with dirt and mud.
ii. Old or rancid olive oils (often characterized by a wax crayon-like taste) are the result of inadequate storage and exposure to damaging light, heat or air.
iii. A grubby or dirty tasting olive oil is likely contaminated by larvae. When olive flies lay eggs in developing olives, the larvae feeds on the pulp—and end up getting processed into the oil.
Harvest: A Harvest Date (not Best By date) on your bottle is a key indicator of transparency and quality.
Polyphenol counts: Extra virgin olive oils range between 100-250 mg/kg polyphenols. If you find extra virgin olive oils with higher counts (like Brightland at the time of harvest), even better.
Bottles: Look for bottles made of UV-protected glass (like Brightland) or stainless steel.
Words: Be wary of meaningless terms on labels, like light, pure, refined, virgin, first cold-press.