YOU PROBABLY CAN’T taste the difference between a $25 bottle of olive oil from a small Sicilian producer and a $10 Trader Giotto’s one. But sample olive oil infused with seasonings — say, tangy garlic or fresh basil — and your mouth will go on a delicious Mediterranean trip.

“Infused olive oil is perfect for when you create a recipe and you want to add more flavor,” says Claudio Pirollo, owner and chef of the Palisades‘ Belgium-French eatery Et Voila! (5120 Macarthur Blvd. NW; 202-237-2300), which prepares some dishes with its own basil-, curry- and peppercorn-infused olive oils.

Oils in which herbs, spices or flavorful fruits and veggies (think garlic, lemons and oranges) have been cooked and steeped for days, weeks or even months can add a new layer of Mediterranean zest to dishes. A rosemary-spiked oil makes a refreshing addition to a grilled salmon fillet; a citrus-powered oil nicely complements roasted potatoes. And dipping warm, crusty bread into basil-infused oil — mamma mia!

Infused oils originated with the ancient Egyptians, Greeks and Romans, who believed that oil from olives had magical, medicinal powers that helped preserve youth. (It turns out, they weren’t far off; “liquid gold,” as Homer called olio, delivers antioxidants and helps promote heart health.)

The oils of yore were steeped with fragrant herbs — everything from fennel to juniper to sage — and used in cosmetics and medicines.

On modern tables, infused oils have gained something of a gourmet status. And they’re popping up on the shelves of local specialty food stores and on the menus of plenty of restaurants.

Customers at Arlington‘s Extra Virgin restaurant (4053 Campbell Ave.; 703-998-8474) are hooked on the house-made kalamata olive-imbued oil tapenade, which is served as a dipping sauce for bread. Made by mixing a puree of kalamata olives, brine from the olives and extra-virgin olive oil, the blend is so popular that the restaurant bottles and sells it (12 ounces for $12; 16 ounces for $18). “It’s a robust but balanced flavor of the kalamata olive and the extra-virgin olive oil,” says executive chef Paul “Chefario” Fario. “We wanted to showcase the whole olive — from the flesh to the oil itself.”

Oil experts say there are plenty of interesting flavors in even the simplest infusion. Olio2go, a Fairfax City Internet retailer that imports olive-oil products from Italy, sells about a dozen types, from chili-peppered concoctions to rosemary-flavored EVOO.

“Our really popular oils are white and black truffle oils,” says Luanne O’Loughlin, manager of Olio2go. Also big sellers: lemon-flavored blends, which get their citrusy goodness from lemons pressed with the olives and then milled.

To put one of these bold blends on your table, check out the infused oils at A. Litteri (517 Morse St. NE, 202-544-0183), a tiny Italian market tucked into a huge warehouse in Northeast. A range of bottles line Litteri’s floor-to-ceiling shelves, including more than 100 brands of regular oils for sale and a handful of infused ones. Owner Mike DeFrancisci particularly favors DeLallo‘s garlic-flavored oil, which is produced in Pennsylvania but tastes like something you’d chow down on in Tuscany.

In the kitchen, infused oils can seamlessly substitute for regular olive oils. Just be sure to stick to the bottles’ expiration dates to keep flavored oils as fresh as possible. And like all culinary oils, infused varieties are most piquant when kept away from heat and light — factors that can make an oil go bad before it reaches its normal 18-month life span, O’Loughlin says.

Of course, once your untrained taste buds meet an infused oil, we’re betting you won’t have any trouble polishing off a bottle anyhow.

» EVOO BY YOU: Want to create your own flavored oil? To avoid health risks, most experts say it’s best to mix spices and herbs into small amounts of oil, and then to consume the blend within days. After choosing a good base oil — maybe a peppery variety from northern Italy or a smooth Sicilian one — raid your spice shelves for dried basil or oregano; chop up fresh garlic and onions; and then take a zester to an orange. Then, stir flavorings into a generous portion of olive oil. Or, take inspiration from Potenza (1430 H St, NW; 202-638-4444) chef Bryan Moscatello‘s blend, which zings with chili flakes and paste, toasted fennel seeds, roast garlic, shallots, garlic, oregano and balsamic vinegar. Both A. Litteri and Olio2go also hawk ready-to-go spice blends.

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