Buying and Storing Oils:
Lile says the “real deal” olive oils have not only an expiration date, but also the date on which they were bottled, too. Often, good oils will also show a lot number on the bottle.
Ernce warns against keeping olive oil next to the stove: “Light and heat denatures the flavor,” he says. His recommendation for a high-priced oil? Keep it in the fridge.
Is it rancid? When olive oil goes bad, it doesn’t become poisonous, but the color and flavor deteriorates. Lile says all the health benefits go with it. To make sure your oil isn’t rancid, slurp it so it hits all your taste buds, inhale and breathe out your nose. “If it makes you cough a little and has a peppery taste, all of the living, healthy things in the oil are still awake and alive,” Lile says.