Olive oil debates might start reheating, with a long-awaited International Trade Commission (ITC) study noting that a lack of standards enforcement has led to "a long history of fraudulent practices".
It turns out that "extra virgin" may not be so innocent, after all.
After a year-long study, the ITC concluded that relatively loose and widely unenforced standards "allow a wide range of oil qualities to be marketed as extra virgin".
Investigators warn that the resulting "adulterated and mislabelled products" hurt US producers, who compete with lower-cost imports by touting higher quality.
"Many producers believe that broad and unenforced olive oil standards work to the advantage of unscrupulous producers and fail to benefit both high-quality producers and olive oil consumers," the trade commission noted.
Competing studies offered by importers and US domestic producers underscore the conflict.
The North American Olive Oil Association, which represents the importers that dominate the US market, cites random testing of supermarket samples that shows less than two per cent of the oils sold as extra virgin have evidence of adulteration. Likewise, less than 10 per cent of samples taken by the International Olive Council show "chemical anomalies" that might suggest mislabelling.
"On the other hand," the trade commission noted, "an analysis by the University of California-Davis concluded that 73 per cent of samples from the top-selling brands failed sensory tests - taste and aroma - for extra-virgin olive oil".
The UC-Davis researchers further found that 28 per cent of samples failed at least one chemical test for extra-virgin olive oil, the trade commission noted.
"Extra virgin" refers to the highest-quality olive oil, which can't be diluted and must be processed mechanically rather than with chemicals. Quality tests include assessing taste and smell, as well as checking for trace chemicals. Often, the commission noted, US consumers don't know enough about olive oil to reliably judge its quality.
"It looks like the report largely corroborates the US industry's view of what's happening," Gregg Kelley, the chief executive of California Olive Ranch in Chico, California, said.
"We're hopeful that this serves as an impetus to action."
Kelley added that "we're ready to work with the federal government and the importers," though a number of key questions remain unanswered with the release of the ITC's 282-page study.
These questions include how US trade officials will handle future negotiations with subsidising European nations and whether US producers will pursue an olive oil-marketing order, setting industrywide quality standards.
"We believe consumers deserve to understand the quality of the oil they are buying and trust its authenticity, and producers deserve fair access to consumers in markets both here and abroad," Kimberly Houlding, the executive director of the American Olive Oil Producers Association, said in a statement.
A representative for the olive oil importers couldn't be reached for comment. In earlier oral and written testimony, the North American Olive Oil Association has warned against "increased testing costs" and "delays at the port" that could result from new quality-testing regimes. The organisation also has raised concerns that certain tests may be unreliable.