What extra virgin means on a label, in plain words

Extra virgin sounds like marketing, yet you can look up its definition, and it has numbers attached. Two documents carry most of the weight, the International Olive Council trade standard and the USDA grade standard, and on the main points they agree. An oil has to clear three hurdles to earn the name. It must be made a certain way, stay inside some lab limits and then pass a tasting panel.

How the oil was made

Virgin oil starts with how you get it out of the olive. Both standards call for mechanical or other physical means alone, under conditions that do not alter the oil, and heat is named as one of those conditions. After that, the only treatments allowed are washing, decantation, centrifugation and filtration. Additives are not permitted.

You can see that rule at work in everything else with olives on the label. Refined olive oil is made from virgin oil by refining, and the USDA describes it as flavorless and odorless. A bottle sold as plain olive oil is a blend of refined and virgin oil. The USDA ranks it below the virgin grades. Olive pomace oil is taken from what remains after pressing, using solvents or other physical treatments. Both standards say it cannot be labelled simply as olive oil.

The lab limits

Free acidity is the number most people have heard of. For extra virgin, the International Olive Council sets a limit of 0.80 grams per 100 grams, expressed as oleic acid, and the USDA uses the same figure. Virgin oil is allowed up to 2.0 grams. The USDA says this number reflects the care taken in making the oil and the quality of the fruit going in.

Acidity is only one line in a long table. Both standards also cap the peroxide value, a measure of oxidation, at 20. They set limits on ultraviolet absorbency too. A further run of purity tests looks for things that should not be there. The USDA notes that sterol and wax tests, for example, help detect seed oil or pomace oil. European rules cover the case where a label does print a result. Regulation 29/2012, as kept in UK law, allows a maximum acidity figure only if the peroxide value, wax content and ultraviolet absorption appear beside it. They must be in the same size of lettering.

The tasting panel

What makes this grade unusual is that people have to taste it. The International Olive Council makes this claim in its guide for consumer tastings. It calls olive oil the only food whose sensory characteristics are legislated as part of its official classification. Under its tasting method, 8 to 12 trained tasters score each oil on a 10 cm line for faults and for good qualities.

Once the scores are in, two results decide the grade. For extra virgin, the median score of the strongest defect must be 0.0 and the median score for fruitiness must be above 0.0. Put simply, the middle of the panel has to find nothing wrong and some fresh olive. The method lists faults such as fusty, musty, winey and rancid. The USDA says rancid gives oil a varnish, paint or seed-like flavor and odor. An oil with a defect median above zero and up to 3.5 drops to virgin under the international method. The USDA draws that line at 2.5.

The test leaves some things open. Extra virgin says nothing about strength or style, so a mild oil and a strongly bitter one can both qualify. The method keeps separate optional terms for that, such as delicate and medium. They depend on the panel's scores and are certified on request. UC Davis says a fresh extra virgin can smell grassy and taste fruity, bitter or peppery, and an oil can lean heavily on any of those.

What the words on a bottle cannot promise

A grade on a label is a claim, and UC Davis says plainly that the label alone cannot prove quality. The USDA standards are themselves voluntary, and the international one is written for oils in international trade. The USDA does guard its own wording. Only its federal inspection service can approve the designation of U.S. grades, on application and for a fee.

Some years ago, a well known test compared the grade with what was in the bottle. A 2011 UC Davis report looked at oil bought in California supermarkets. Of 90 samples from the five top-selling imported extra virgin brands, 66 failed two accredited sensory panels. None of the California or Australian samples failed both. The failing samples showed defects such as rancidity and fustiness. Only about a third of them also failed the Council's ultraviolet test, and the report said its other common chemical standards did not help confirm the bad results.

Age is the other limit, since a label is printed once and the oil keeps changing. UC Davis notes that time, oxygen and light can turn oil rancid. A bottle that met the grade when it was filled can drift away from it. Your own palate may not catch that without practice. In a UC Davis consumer study, more than four in ten participants liked oils with rancid flavors. Those flavors would disqualify an oil from the grade.

Some words and marks can tell you more. The California Olive Oil Council seal requires chemistry and sensory testing after every harvest. Its limits are 0.5 for free acidity and 15 for peroxide, tighter than the international figures. Dan Flynn of the UC Davis Olive Center recommends noticing seals like this one. Cold pressed has a real meaning in the European rule, too. First cold pressing is allowed only on extra virgin or virgin oils made below 27°C from a first mechanical pressing with hydraulic presses. Cold extraction covers oils made below 27°C by percolation or centrifugation.