Evaluating Olive Oil: Not Just About Taste
If you would like to be a better taster, evaluating olive oil is a good way to train. Extra virgin olive oil exhibits a large range of sensory attributes that trained panelists can identify with precision. In Europe, the highly trained judges for the International Olive Oil Council—the people who award the extra-virgin certification—can accurately rank a batch of oils by degree of bitterness or pungency. (Try it; it's not easy.)
Sensory scientists like Jean-Xavier Guinard, a professor at the University of California at Davis, remind us that sensory analysis is about more than just taste.
"Taste is a limited range of sensations," says Guinard. Sweet, sour, salty, bitter and the savory sensation known as umami are the only tastes our palates discern. When we "taste" foods or beverages, we actually send our brains a lot more information—about apppearance, aroma and texture—which it integrates before identifying the sample and passing judgment. With olive oil, as with many other foods, "most of the sensory experience will be an olfactory experience," says Guinard.
When professionals evaluate olive oil, they don't even consider appearance. They taste from blue glasses so they can't see the oil's color as it has no bearing on quality.
They examine the sample first for defects, because an oil with any flaws in aroma or taste can never be certified extra virgin. To help you identify the more common defects, here are the words professionals use to describe them: musty, winey/vinegar; acid/sour; muddy sediment; metallic; rancid; and fusty, a word that refers to an unpleasant fermentation smell that can arise when the olives aren't pressed soon after harvest.
The most important positive attribute is fruitiness. The sample may have "fruity-green" notes like grass and artichoke, or "fruity-ripe" notes like almond, but it must have some fruitiness. Bitterness and pungency are also desirable, although many novice tasters object to these qualities.
Pungency—that peppery bite that can make you cough—is a key attribute of some olive oils, says Guinard. The riper the olives at harvest, the less pungent the oil. Tuscan oils are renowned for their pungency. Many fine olive oils are not nearly as pungent as the Tuscans, but tasters don't mark an oil down for being pungent unless that quality overwhelms the fruit.
Bitterness is naturally present in olive oil (have you ever tasted an olive right off the tree?) and it tends to correlate with pungency. Although an olive oil's artichoke-like bitterness may strike you as unpleasant when you taste the oil on its own, remember that it won't be served that way. The oil might be drizzled over grilled fish or hot bruschetta, where its bitterness won't be as pronounced.
Worth noting: Olive oils that rate high in bitterness and pungency are also high in antioxidants, the compounds that preserve freshness and have some cancer-fighting properties. Buttery, low-pungency oils won't last as long.
