It is possible go into virtually any bar and order a Black and Tan. And if recent growth continues, soon it may not be the only blended beer available.
In the ever-expanding universe of craft beer, the practice of blending two or more beers together is currently experiencing a renaissance. Of course, bartenders and brewers have been blending beer for centuries. In Belgium, Gueuze style beers have always been created by combining and refermenting old and young Lambics. The first Black and Tans popped up as early as the 18th century, with pub goers ordering a mix of dark and light beers.
Contrary to popular belief, Black and Tans did not originate in Ireland, but in England. (In fact, the term Black and Tan has a very negative connotation in Ireland since that was the same name of a British force that once terrorized the country.) Typically, 50 percent of stout or porter is mixed with 50 percent of bitter, pale ale, or pale lager, producing a flavorful, yet easy-drinking session beer. By far the most common version involves GUINNESS DRAUGHT and BASS PALE ALE.
While most countries simply mix the beers together, in the United States Black and Tans are carefully separated. You start by vigorously pouring half of the Bass into a pint glass (producing a sizeable head will help to separate the beers.) Next, hold a spoon over the glass and flip it upside-down, pouring half of the Guinness slowly over the bottom-side of the spoon. If you are careful not to disturb the "tan" on the bottom, the "black" should layer distinctly on top, giving you a beautiful Black and Tan!
Obviously, some science is at work here. Although it may not look like it, Bass and most other Pale Ales actually have a higher specific gravity (or in non-home-brewing-terms, weight) than Guinness. Guinness' low gravity makes countless other layered blends possible, including "Half and Half" (Guinness and Harp), "Black Castle" (Guinness and Newcastle), "Black Smith" (Guinness and Smithwick's), and "Black and Blue" (Guinness and Blue Moon).
If a bartender can dream up these beers, so can you! I have conducted several exbeeriments (thank you, thank you) with varying success with several of my favorite Stouts and IPAs. Instead of Blue Moon, I've also tried a "Black and Blue" that substituted SEA DOG BLUE PAW WHEAT ALE. That didn't work for me. What did work was a "Black and Red:" Guinness and LINDEMAN'S FRAMBOISE, a raspberry lambic; 20 percent Framboise is more than enough to give this old favorite a sweet new twist.
Not surprisingly, several brewers have attempted to capitalize on the popularity of Black and Tans with bottled versions. YUENGLING BLACK AND TAN is the most visible example, a mixture of their porter and traditional lager. Like many of the bottled Black and Tans, the darker beer dominates and this ends up feeling like a watery porter. MISSISSIPPI MUD is also porter and pilsner, but the most interesting part of this beer is the gimmicky moonshine jug that it comes in. In fact, the only decent bottled Black and Tan that I've had was BERKSHIRE'S "SHABADOO" BLACK AND TAN ALE. Roasted malts, an edge of bitter hops, 6.3% ABV, creamy mouthfeel, drinkability — this beer has it all!