If it smells like crayons, don't get it
Olive oil is an absolute pantry essential, but a lot of people aren't buying the good stuff. Much of the time, according to Epicurious, what you think of as pure olive oil is being diluted with other neutral oils, like soybean oil, altering the taste and the quality in every way. Recently-harvested olive oil can also be combined with olive oil from an old harvest, which means the quality won't be as high and the shelf-life will be drastically shortened.
However, identifying an olive oil that's worth your while is pretty easy, as long as you know what to look for. I had the chance to chat with California Olive Ranch's oleologist Maia Hirschbein about what you should pay attention to the next time you buy olive oil.
First of all, take a look at the actual vessel the olive oil is stored in. Plastic bottles aren't great. Ideally, you should choose an olive oil in a dark glass or metal container. Hirschbein says that both materials "protect the oil from the damaging effects of light exposure." You should also make sure the vessel can be tightly sealed, as exposure to oxygen can degrade the oil as well.
Secondly, read the label. Make sure the olive oil you choose is clearly marked as extra virgin olive oil, the highest quality grade of olive oil. Ideally, you should also see a harvest date on the bottle: Make sure it lists a date within the last year.
What You're Doing With It
Thirdly, think about how you'll use the olive oil. Often, a good everyday olive oil—that you use for all sorts of cooking and baking efforts—will be identified as "mild" on the label or in its tasting notes. Hirschbein says that a good olive oil like this should be "priced to use liberally—in the $9 to $15 range." It's nice to have another spicier or fruitier olive oil on hand to use as a finishing oil for pizza, salad dressings, or pesto, if you feel like it. It'll be more expensive, but will also be used more sparingly.
How to Store It
Also keep in mind the ideal storage conditions for olive oil, both while you're purchasing it and when you bring it home. Make sure your olive oil is—and has been—kept away from heat or light sources. So, don't store it by the stove or on a window sill. In a cupboard or cabinet is best. While unopened olive oil can last for up to two years in good conditions, once a bottle is opened, Hirschbein advises, "it should be consumed within one to two months."
How It Should Smell
Extra virgin olive oil should "smell fresh, like fruits or veggies," Hirschbein says. "It should taste slightly bitter and should give a little bit of a burning sensation in the back of your throat." A rancid olive oil will "smell dull, like crayons." Olive oil is basically fresh juice, so like all fresh products, oil is at its best for a finite amount of time. As such, don't buy a huge bottle of the stuff if you're not going to use it all within a couple months.
Once you start using the good stuff, you'll probably find it hard to go back to subpar olive oil. But in my opinion, that's as it should be: If you're using olive oil every day, it should be something special.