If you're up on your Irish history, you know that singing the praises of Black and Tans in an Irish pub might land you some icy stares, if not a mouthful of bloody teeth. But if you must, make sure those praises are for the classic combination of ale and stout, and not for the khaki-uniformed men of the Royal Irish Constabulary during the Irish Civil War of the 1920s.
That being said, most bartenders this side of Dublin won't take umbrage. The Black and Tan is considered by most to be an American affectation, though the drink itself dates back to British pubs in the 1800s, when beer drinkers sought to balance stout with lighter beer styles. It's a popular pint today for the same reasons: it produces new flavors and textures, and is a great way to get a dose of stout when a full pint is too heavy.
Often served as equal parts ale and stout, the Black and Tan is properly served as two-thirds ale and one-third stout. The ale is sipped through the stout, which is poured over an upside-down spoon to create a layered effect. (Much to many people's surprise, the density of Guinness is less than ale, allowing it to settle on top.) The separation is distinct, and anyone who has ordered one before knows there is theater about watching Black and Tans settle.
Black and Tans are most often made at bars using draft beer, but making them at home is easy with the Bass Brolly, a triangular tool that when set on the rim of the glass allows even an amateur to pour a decent Black and Tan. (And it's easier to use than a spoon turned upside down.) After filling a pint glass three-quarters full with ale, rest the Brolly on top of the pint glass, crack open a stout -- Guinness draft cans or the stout of your choice -- and pour it through. The holes in the Brolly allow for a gentle pour, creating that perfect separation between ale and stout.
The classic Black and Tan combination is Bass pale ale and Guinness stout, but that doesn't mean you shouldn't experiment. The all-Irish Black and Tan -- Smithwick's and Guinness -- is a popular alternative, as is the Half and Half, which is typically Harp and Guinness, but can be made with any lager you choose (the All-American is Budweiser and Bareknuckle Stout). Another option is to substitute Guinness and a craft-brewed stout. With several from which to choose, including chocolate and oatmeal stout, the combinations are endless. Some work better than others, of course, in terms of separation (oatmeal stout tends to blend into the ale and form one color, similar to bottled versions of Black and Tan) and flavor, but that's why research is so much fun.
The bottom line is, why drink green beer this St. Patrick's Day when you can drink Guinness, and why drink only Guinness when you can combine it with ale or lager? The choice is yours, but if you order a Black and Tan, be prepared to back it up with a healthy shout of "Up the Republic!"