Millennials have been accused of killing canned tuna, motorcycles and diamonds. But they're actually helping at least one industry: Irish whiskey.

Over the last five years, the volume of Irish whiskey sold in the U.S. grew by 61 percent, according to the Irish Food Board. In 2018 alone, sales grew by 9.4 percent compared to the previous year, netting distillers roughly $1 billion in revenue.

Last year also marked the ninth straight time that spirits took market share from beer, according to David Ozgo, the Distilled Spirits Council's chief economist.

American millennials are driving the growth of Irish whiskey in the U.S., in part, due to their willingness to spent more on higher quality alcohol, Ozgo said.

Despite its growth in the U.S. and elsewhere in the world, Irish whiskey still represents less than 3 percent of the case volume of all spirits sold. But spirits companies are trying to change that, spending more on marketing pushes for their brands. For example, when Diageo, the world's largest spirits purveyor, re-entered the booming market in 2017 with Roe & Co., it increased its marketing spending by 20 percent compared to the previous year.

Irish whiskey tends to be smoother and less smoky than its Scottish cousin scotch and less sweet than American and Canadian varieties.

Jameson, owned by French spirits giant Pernod Ricard, remains the market leader. But there are some upstarts looking to make their own mark on the space. In 2013, there were just three distillers in Ireland: Cooley, Irish Distillers and Dingle Distillery. Now, there are 18 facilities with eight more on the way, according to the Irish Food Board.

Ozgo also noted that cocktails featuring Irish whiskey have become more popular menu items over the years. New York City's The Dead Rabbit, named the World's Best Bar in 2016 by Drinks International, devotes about half of its menu to such cocktails, but its bartenders are also trained to help customers learn more about the alcohol.

"What I generally see is, people say whiskey as a general term, and then that's where we say, 'Well, Irish whiskey is a huge part of our DNA and what we're known for,'" said Jillian Vose, the bar's beverage director.