Caffeine, booze, sugar? It’s a match made in Irish heaven.

You don’t need a specific, shamrock-adjacent date to enjoy Irish Coffee. They’re poured year round at San Francisco’s Buena Vista Cafe, where then-bar Jack Koeppler and San Francisco newspaper columnist Stanton Delaplane introduced the whiskey-based cocktail to the U.S. in 1952.

At the Buena Vista, the drink is made with 1.3 ounces Tullamore Dew whiskey, two sugar cubes and 4 to 6 ounces of Oakland’s Peerless coffee. It’s topped with heavy cream, whipped to a soft froth and poured over the back of a spoon to achieve the signature float.

But there are variations a’plenty. Some bars tinker with ratios. Others play with the sugar — skipping sugar cubes in favor of a simple syrup, for example, made by simmering equal parts demerera sugar and 1 cup water for a few minutes.

Some dabble with cream whipping techniques. The Buena Vista uses a blender. Bay Area bartender Wesley Quinlan uses a cocktail shaker with a Hawthorne strainer to whip the cream and sweetens both the coffee and the cream with demerara.

And while some vary the whiskey, others use a different spirit altogether. America’s Test Kitchen does the classic but offers suggestions for making a Caribbean or Italian version, too. So if you’re not feeling the luck of the Irish, the fortuna of the Italian might send you in an amaro-tinged direction.

Here are the how-tos for that.

Irish Coffee

Makes 1 cocktail

INGREDIENTS

2 ounces heavy cream

¾ ounce simple syrup, divided

4 ounces brewed hot coffee

1 ounce Irish whiskey

DIRECTIONS

Whisk cream and ¼ ounce simple syrup in a chilled bowl until soft peaks just begin to form, about 30 seconds; set aside.

Add coffee, whiskey and remaining ½ ounce syrup to a warmed glass mug and stir to combine. Dollop whipped cream over top. Serve.

Twists

For a Caribbean Coffee, substitute orgeat — the almond-flavored syrup used in mai tais — for the simple syrup and aged rum for whiskey.

For an Italian Coffee, use a lemon-infused citrus syrup and an amaro.

— Adapted from America’s Test Kitchen