America is awash with Irish whiskey

If Irish eyes are smiling at the approach of St. Patrick's Day, the widest grins this year may come from the Emerald Isle's distillers as their signature product continues on an increasingly prosperous path.

Irish whiskey is far and away the fastest growing spirit in the U.S., expanding beyond an annual ritual shot to become year round tipple. According to data compiled by the Distilled Spirits Council, an industry trade group, volume has jumped from just over 400,000 cases in 2002 to more than 2.5 million last year. While that total still lags behind bourbon, scotch and Canadian, the trajectory shows no signs of slowing down.

"It is still gaining momentum," said Tom Pirko, president of industry consultancy Bevmark. "We are right at the beginning of it."

Pirko believes that one of the reasons for the boom is that "people are turning back to things that are authentic, products that have more flavor that than vodka. And Irish has the potability without the bourbon burn or the peaty quality of scotch. It is kind of like Canadian, but with quality."

While the Irish claim to have invented whiskey – something many Scots are apt to vigorously dispute – ownership of the major producers has long since passed into foreign hands. Jameson, the runaway No. 1 brand with a roughly three-quarters share of the market, is controlled by France's Pernod Ricard.

Runner-up Bushmills is part of the portfolio of British beverage giant Diageo, which also owns Guinness. Other players include the U.K.'s William Grant and Beam, the American spirits firm that is about to be swallowed up by Japan's Suntory.

Most have turned modest investments, often made many years ago, into potstills of gold.

Jameson recently poured about $130 million into expanding their distillery, a move that their Irish whiskey marketing chief Paul DeVito said was a statement of confidence in the category's future.

"While it is true that Irish is taking consumers from bourbon and Scotch, it is also true that t! hose categories are growing too," he noted. "But Irish is also benefiting from the rising tide of new whiskey drinkers [and from] consumers' increasing interest in brown spirits overall."

The company has been rapidly expanding its product line, most recently with the introduction of Jameson Black Barrel, a higher-priced, higher-margin expression of their day-to-day hooch.

Beam entered the ring late with its 2012 acquisition of Cooley Distilleries, something that Kevin George, the company's chief marketing officer, said "was a natural play considering the whiskey boom around the world. It is a mixable, drinkable whiskey [that is] lighter and sits somewhere between scotch and bourbon."

George, who oversees brands including Kilbeggan, Connemara and the recently-acquired 2 Gingers, noted that Irish whiskies are currently growing by 18% in dollars and 16% in volume each year "and we definitely think that will continue."

David McIntyre is the senior vice president of food and beverage at MGM Resorts, a Las Vegas-based gambling chain that garners about $1.5 billion annually from its myriad restaurants and bars. It is among the largest purveyors of booze in the country. While vodka remains their biggest seller, Irish whiskey is coming on strong.

"It is a really good introductory spirit," he said. "Sweet and light and easy to mix."

McIntyre said that the properties he manages are tracking along with national trends. And while he does not see any signs of a slowdown, he does think it will overtake bourbon or scotch anytime soon.

"The irony, of course, is that John Jameson was a Scotsman," McIntyre said.