Company president Paul Macaluso said limited-time offers like the bourbon-flavored milkshakes can boost sales at Krystal by as much as 40 percent.
"We know that our guests crave new and vibrant flavors and have come to expect our menu innovation to be playfully Southern," Macaluso told the Times Free Press. "Our new maple bourbon shake over-delivers on that expectation and is absolutely delicious."
The milkshake is an attempt by Krystal to reverse two years of lagging sales, the newspaper reported. The company introduced pimento cheese bites and frozen Lemonhead slushies during a two-month summer promotion that ended in August.
Krystal opened its first restaurant in downtown Chattanooga in 1932 and claims to be the second-oldest fast-food chain. White Castle is the oldest, founded in 1921.