From coeds to day laborers to Cary Grant in “His Girl Friday,” imbibers spanning continents and generations find the lure of a spiked coffee drink in its very definition — the marriage of two favorite vices. “It was the Italians who first recognized the appeal of ‘correcting’ coffee with a shot of liquor — caffe corretto in Italian,” says Michael Turback, author of “Coffee Drinks” ($14.95, Ten Speed Press). “In a culture that takes eating very seriously, the stimulating, after-dinner spiked coffee provides both an excuse to linger longer and an aid to digestion.”

Italians tend to reach for sambuca, cognac and grappa, Turback says. But the coffee-booze combo most famed in the U.S. is whiskey-fortified Irish coffee, invented by an Irish airport bartender on a winter night in the 1940s.

P.J. Clarke’s (1600 K St. NW; 202-463-6610) serves the classic recipe — two teaspoons of brown sugar, a cup of hot coffee, a shot of Jameson and fresh, heavy cream (never whipped!) floating on top. “The brown sugar gives it extra buoyancy,” says general manager Dave Lovett. “It almost looks like a miniature pint of Guinness.” For nontraditionalists, P.J. Clarke’s also offers twists on the iconic cocktail, starring Baileys, Kahlua and even rye whiskey.

As in Italy and Ireland, throughout the afternoon, Cuban workers line up at coffee stands for shots of espresso. “It’s their culture,” says Bob Gallo, vice president of operations at Havana-gone-hip Cuba Libre (801 Ninth St. NW; 202-408-1600). “Drinking coffee is how they get through the day.” And as evening wears on, he says, out comes the rum.

Steamed coconut milk and spiced rum enhance robust Cuban coffee in the restaurant’s decadent signature sip, the Cafe Cuba Libre. Richer yet, the Mulatta cold dessert cocktail combines espresso, cream, Kahlua, Godiva chocolate and Cruzan blackstrap rum, garnished with a Hershey’s kiss.

Like the drink makers at Cuba Libre, home bartenders are wise to take cues from the complex flavors of coffee. And for the best results, baristas say to skip watered-down diner sludge and use high-quality coffee. It’s essential for the java to be able to “hold its own” against the liquor, Turback says. “Use strong, dark-roast coffee in a spiked drink,” he says. “The proportion should be at least five-to-one, coffee-to-liquor.”

Modern mixologists let caffeine fuel their creativity. Jose Andres’ team at Jaleo spikes coffee with Torres orange liquor and brandy. Steve Oshana, bar manager at SOVA (1359 H St. NE; 202-397-3080), offers a trio of spiked coffee drinks. The Armenian coffee lover adds toffee-infused Armenian brandy, cardamom and vanilla bean syrup to Turkish coffee for a drink he calls Bridge to Ararat. A nod to his former days in the Windy City, the richer-than-Donald-Trump cocktail Intelligent Design stars Intelligentsia coffee, mint-infused cognac, Vosges chocolate truffle liqueur and caramel foam. And Oshana’s Family Gathering? The hopped-up Manhattan features Four Roses bourbon, espresso-infused vermouth and candy cane bitters.

Surprisingly, making espresso bitters is simpler than, well, ordering a drink at Starbucks. Oshana says the process can be done two ways. Simply pour two parts vermouth to one part espresso for an instant add-in. More patient bartenders can let espresso (or coffee) grounds steep in vermouth overnight for a more natural infusion. Strain the mix using a coffee filter, cheesecloth or even a water filter.

More unconventional coffee pairings Oshana likes: Drambuie (a Scotch-based honey liqueur), lemongrass, lavender (throw petals into the grinds for a “sweet herbal flavor”) and even basil.

The beauty of a cup of joe, Turback says, lies in the endless possibilities. “Additional components add to the complexity of spiked coffee — coffee brewed with chicory marries well with brandy; stirring a rum-spiked coffee with a cinnamon stick adds a compatible spice. A spoonful of shaved dark chocolate sweetens Irish coffee.”

As you experiment, though, be wary of the heady blend of alcohol plus caffeine. (It’s no coincidence that college students call boozy energy drinks “blackout in a can.”) “If you’re going to be drinking a lot,” Oshana says, “try decaf.”

Recipe Files

Mezcal Cafe su Da
Christopher Carlsson, Spirits Review, Rochester, N.Y.
3 tbsp espresso-flavored sugar (Stirrings Espresso Rimmer preferred)
1 oz sweetened condensed milk, more for the glass
Ice cubes
1 oz Scorpion Silver Mezcal
4 oz strong coffee, cooled

Makes 1 serving
Place the espresso-flavored sugar on a flat plate. Moisten the edge of an 8-ounce glass with a bit of the sweetened condensed milk, then dip the rim into the mixture and rotate the glass until evenly coated. Add the 1 ounce of sweetened condensed milk to the bottom of the glass. Fill with ice cubes. Add the Mezcal and coffee. Stir and serve.

Cafe Cuba Libre Especial
2 oz rich espresso
3 tsp sugar on the raw
2 oz coconut milk
2 oz whole milk
Finished with 3/4 oz Cuba Libre Spiced Rum

Coco Cream con Xocolati
2 oz rich espresso
3 tsp dark chocolate
4 oz whole milk
3/4 oz Cruzan Rum Cream
3/4 oz Bacardi Coconut Rum
Top with whipped cream

Reprinted with permission from “Coffee Drinks” by Michael Turback. Published by Ten Speed Press, a division of Random House Inc.

Written by Express contributor Katie Knorovsky
Photos by Lawrence Luk