Fetid milk, stale walnut, and baby vomit are all words you probably hope don't define your EVOO, yet they represent just a tiny fraction of the colorful vocabulary that the experts use to describe the aroma and taste of olive oil. Fret not. There are far more pleasant terms used for the same purpose: think ripe tomato, cinnamon, and passionfruit. I recently met with Joeli Yaguda, owner of award-winning extra virgin olive oil producer Pasolivo, who let me know exactly what to look for. The International Olive Oil Council uses these techniques for its assessments, but you can simply try them at home to determine if you have a quality product in your pantry.
Start by warming the oil. Do this by pouring a couple teaspoons of olive oil into a small glass then cupping the top and bottom with your hands for several minutes. Once you feel the glass heat up, swirl the oil around and take a whiff. You can then look at an olive oil tasting wheel (The Olive Oil Source provides one version online) to determine some key attributes. A good olive oil should smell fruity, an indicator that it comes from sound, fresh olives. You will perceive this aroma directly, or through the back of the nose.
After smelling, take a small sip and let the oil sit on the back of your tongue, then slurp air into your mouth to blend with the oil. It should be bitter on the back of your tongue. The last trait to look for is pungency, which will create a peppery sensation in the back of your throat. Note that these positive attributes should be well balanced. Extremely fruity but only slightly bitter or very pungent and barely fruity, for example, may not be the makings of an all-star oil.
Also pay close attention to tastes or smells that indicate a low-quality oil: musty or moldy, winery/vinegary, rancid, burnt, greasy, brine, earthy, grubby, cucumber, metallic.