Avoid anything in a clear glass bottle, no matter how pretty and enticing the label.
Light is the great enemy of olive oil and the oil inside will likely have lost most of its flavor and aroma. Look for extra-virgin olive oil in dark glass bottles or opaque tins.
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 flavors 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, but not the fridge.
Use your oil!
And don’t be afraid to cook with extra-virgin. It is perfectly stable up to about 420ºF. 360ºF is the optimum temperature for deep-frying, you can use extra-virgin comfortably for almost all of the cooking. And because it doesn’t get better with age, use it up!
Use it liberally!
Use it in place of butter for almost everything! Cook your eggs in it, drizzle it on popcorn, put it on your morning English muffin, give your pup a tablespoon of it each day. Try it drizzle over fish with fresh herbs and salt, brush it on corn on the cob! Drizzle a strong, peppery olive oil over really good ice cream or gelato for a taste-bud explosion!