Choosing an olive oil from a shelf of bottles at wildly varied price points can be challenging. Here are some easy things to remember from olive oil expert (and grower and producer) Nancy Harmon Jenkins, author of Virgin Territory: Exploring the World of Olive Oil.
- Only buy oil labeled extra-virgin. This is not a guarantee that the oil will be the best, but at least it will probably not be among the worst. Bottles labeled just plain "olive oil" and "light olive oil" are refined oils and, like vegetable oil, while they're not bad in any way, they are not very interesting.
- Read the label. Even if it's written in Italian, French, or Spanish, you can probably figure out enough to recognize harvest and "use by" dates. The finest producers always put the harvest date proudly on their olive oil. The use-by date can be a little deceptive since it is usually 18 months from bottling, rather than from harvest.
- Avoid anything in a clear glass bottle, no matter how pretty and enticing the label. Light is the great enemy of olive oil; clear-bottled oil will likely have lost most of its flavor and aroma. Look for extra-virgin olive oil in dark glass bottles or, better yet, opaque tins.
- Know that the term "first cold pressing," although widely used, is redundant. By legal definition, extra-virgin oil must come from the first (usually the only) pressing, which must be accomplished with no added heat (at ambient temperatures no higher than around 80°F).
- Extra-virgin olive oil does not improve with age. Fresher is better, and right out of the mill, olive oil is a fabulous experience. Fresh oil may have unexpectedly assertive flavors of bitterness and pungency that sometimes override the fruitiness. These challenging notes are treasured by connoisseurs because they indicate high quality, and by nutritionists because they're evidence of lots of healthful polyphenols.
- Light is the enemy and so is heat. Keep your precious bottles in a cool, dark environment. I have a couple of tin containers within reach of my stove, each of which holds a cup and a half of oil, enough for a couple of days in my kitchen. They get refilled from the bulk of my oil, which I keep in a cupboard in an unheated pantry.
- Use your oil! Don't be afraid to cook with extra-virgin. It is perfectly stable up to about 420°F. Since The Joy of Cooking says 360°F is the optimum temperature for deep-frying, I use extra-virgin comfortably for almost all of my cooking. And because it doesn't get better with age, I use last year's oil for cooking, and this year's fresh oil for garnishing.
- Use it liberally! Learn to love a hot baked potato, cracked open and topped with lots of the freshest, finest oil you can buy, a sprinkle of fleur de sel, and freshly ground Tellicherry pepper. Or try my favorite Catalan breakfast: grilled rustic bread with a ripe tomato crushed on top, then salt, pepper, and a glug of extra-virgin over it all.
- Buy from trusted retailers who know how to maintain quality. I find the best quality olive oil from online sources. Here are a few of my favorites: Olio2go, Market Hall Foods, Corti Brothers, Zingerman's, and Gustiamo.
