The Irish car bomb (a shot of Irish whiskey and Irish cream dropped into a pint of Guinness) is a standard St. Patrick's Day cocktail, though its origins aren't commonly known.

First of all, it didn't originate in Ireland. In 1979, Charles B. Oat created the drink at Wilson's Saloon in Norwich, Connecticut, according to a booze blogger who studied bartending under Oat.

The original shot included Bailey's, Kahlua and Jameson's Irish Whiskey. It was originally called the Grandfather because it was meant to toast one's grandfather, but the name was soon changed to the IRA because when the shot of liquor is dropped into the beer, the concoction bubbles like an explosion, recalling the bombs the IRA would use in terrorist attacks.

Some bartenders refuse to serve the drink due to the political implications of the name, but for the most part it's enjoyed across the U.S. anywhere binge drinkers gather.

Irish car bomb recipe, via Drink Nation:

  • 1/2 oz. Irish cream
  • 1/2 pint stout
  • 1/2 oz. Irish whiskey

Pour half a pint of chilled Guinness into a beer mug and let it settle. Take a shot glass filled with half an ounce of Irish whiskey (Jameson's) on the bottom and half an ounce of Irish cream (Bailey's) on top. Drop the shot glass into the Guinness and chug.