Kentucky Bourbon is a Growing Attraction for Travelers (VIDEO)

Kentucky bourbon is a billion-dollar business and the drink generated $4.5 billion in retail sales last year, according to NBC News.

Some interesting facts about bourbon, according to NBC, include that ninety-five percent of the world's spirit is distilled in the state; there are more barrels of bourbon aging in Kentucky than there are people and horses living in Kentucky combined. Production of bourbon is up more than 50 percent in the last 10 years as well.

Even with the number of distilleries currently operating in the state, it's still well under the number that operated before Prohibition made alcohol illegal. However, the number is growing along with an increased interest from tourists in seeing the methodology behind making bourbon.

Craft distilleries are "popping up everywhere," Eric Gregory, the president of the Kentucky Distillers' Association, said.

The majority of the world's bourbon - 90 percent - is accounted for from just the top six distillers, known as the "Big Six." These include Jim Beam, Heaven Hill, Wild Turkey, Four Roses, Brown Forman and Diageo. The remaining distilleries are small, family-owned operations.

A new book by Susan Reigler, a writer from Louisville, "Kentucky Bourbon County: The Essential Travel Guide," provides help for tourists looking to figure out where to go.

Small distillery "high points are within striking distance of Louisville," Reigler said in the book.

"If you only have time to go to one, Willet (in Bardstown) is your best bet," Reigler said. "It's so beautiful...on a hilltop, looking over lovely wooded countryside."

Kentucky state law limits bourbon sampling to two. Reigler suggests a method to get around this. "Go with someone who doesn't like bourbon and you can have their samples, too," she said.

The Kentucky Bourbon Trail Craft Tour website provides information on touring small distilleries. According to Reigler, fall and spring are the best times to visit Bourbon County.