Irish Whiskey: St. Patrick's Spirit

March 17, 2011 -- "Oh, whiskey you're the devil/ you're leading me astray/ over hills and mountains/ and to Amerikay!"

The Clancy Brothers may have been led astray -- all the way to America! -- by the amber charms of whiskey. But they were apparently on to something when they scored a hit with the traditional reel "Whiskey You're the Devil."

Ponder this as you tipple your Irish coffee this St. Patrick's Day: Year over year, sales of Irish whiskey in the U.S. have grown faster than any other category of spirit. In 2010 sales of Irish whiskey grew 17.2 percent (in 2009 that number was higher: 21 percent). By contrast, sales of its American cousin bourbon grew 1.2 percent last year and scotch actually decreased by 3.6 percent.

The data, provided by the Nielsen Company, also showed that the only other spirit that enjoyed big gains was vodka, with 15.2 percent growth in 2010. By contrast, rum grew 1.3 percent and sales of gin shrank by 1.8 percent.

"It's very in to drink brown spirits," says Meredith May of Tastings, the trade magazine of the Beverage Testing Institute.

Cocktails, she says, are hip, and so are those macho Mad Men highball drinks on the rocks.

"You see more whiskey bars around LA and San Francisco and New York now. There's more mixology action with the brown spirits. And Irish whiskey is very approachable," May tells ABC News.

Most Irish whiskey is distilled three times, while scotch is distilled twice. Peat is often used in scotch's malting process, lending it a smokier, more earthy flavor than the populist Irish drink. In America, bourbon is made from mash that is mostly corn, giving it a sweeter flavor.

"Irish whiskey doesn't take itself as seriously as scotch, where there's almost this intimidation of 'where is this single malt from? Is it from the Highlands or Lowlands or Speyside'?" says May. "In Ireland there are only three distilleries: Cooley, Bushmills and New Middleton."