Olive oil grading standards set by the Madrid-based International Olive Council are considered the industry benchmark, but while they require lab analysis and sensory tests, they’ve been criticized for being too broad and inadequate in determining factors like the age of an oil.

The Australian Standard for Olive Oils and Olive Pomace Oils—AS5264-2011 for short—goes above and beyond the IOC’s by requiring, among other things, two additional chemical tests not used elsewhere that detect freshness, quality, and whether an oil’s been cut with cheap or old oil. 

The DAG test, which Olmsted calls “the most sophisticated chemical analysis for freshness,” measures the ratio of compounds called diacylglycerols that change with age, heat, and/or the refining process. The PPP test measures the degradation of chlorophyll in the oil, which happens steadily with age but can be manipulated with high heat, say, in the refining process. 

AS5264 also bans the use of misleading label terms such as “pure” and “light,” requires a “best before” date less than two years from when an oil was bottled, and calls for random testing of olive oil at the retail level “in order to capture the degradation that naturally occurs over time,” according to the International Trade Commission. 

The standard aligns with the olive association’s broader Code of Practice certification program (now called OliveCare), in place since 2005, which monitors things like sustainable practices, and which producers agree to follow—voluntarily—in order to carry the “Australian Extra Virgin Certified” seal.

That’s right. None of this is required by Aussie law. But according to Rowntree, about 90 percent of olive oil made in Australia meets these standards. That goes for premium brands like Cobram Estate, a consistent award winner, and supermarket-brand oils, including Aldi Australia.