Bacardi Limited is going shopping again, adding another boutique spirit to its brand portfolio.

The Bermuda-based spirits giant, whose U.S. headquarters is in Coral Gables, will announce Tuesday that it has purchased St-Germain. The premium elderflower liqueur is one of the fastest-growing spirits brands in the United States and a favorite cocktail ingredient at trendy bars.

Bacardi is buying the brand from the Cooper Spirits Co., which is based in New York and also has an office in Palm Beach. Terms of the deal were not disclosed.

The acquisition continues Bacardi’s trend of focusing on the acquisition of super premium brands, including Bombay gin, Grey Goose vodka and most recently a stake in Patrón tequila.

“We, as a company, have a track record of nurturing new and up-and-coming brands,” said Robert Furniss-Roe, president of Bacardi North America, which is based in Coral Gables. “St-Germain is a great complement to our portfolio. We don’t have anything like it. We see a very long runway in front of St-Germain.”

Founder Robert Cooper said he wasn’t actively looking to sell but began having conversations with Bacardi Deputy Chairman Barry Kabalkin about the possibility. Ultimately, Cooper decided that selling to a larger international company would help foster St-Germain’s future growth.

Since its launch in the U.S. in 2007, St-Germain grew by more than 50 percent in 2011 to reach nearly 77,000 cases worldwide, according to IWSR, an industry data source. In 2012, that growth was expected to continue with a projected 100,000 cases in sales worldwide.

“As an independent I could still grow the brand, but I didn’t think I would have the same potential to reach consumers far and wide on an international scale,” said Cooper, 36, who is a third-generation distiller. His family created Chambord liqueur. “For me it’s as much about securing St-Germain’s future. Bacardi is in the best position to take what we’ve started and further build on that success.”

Cooper will not hold any ownership stake, but he will remain available as a consultant to Bacardi and the “brand protector” of St-Germain.

What Cooper wants to ensure is that St-Germain maintains its French hand-crafted, artisanal roots. The liqueur is made from elderflower blossoms hand-picked during a few weeks every spring in France. Only one batch is made annually.

The majority of St-Germain’s business is done in bars and restaurants, where many bartenders consider it one of their go-to ingredients. You’ll find cocktails with St-Germain on the menu everywhere from the Mandarin Oriental Hotel to BLT Steak and the Living Room at the W South Beach.

“It’s the best liqueur to come out in 75 years,” said John Lermayer, bartender at the Regent Cocktail Club at the Gale South Beach. “It goes well with everything. I’ve never seen anything as mixable since sugar. It goes just as well with rye whiskey as it does with Champagne.”

But some of Miami’s trend-setting bartenders like Gabe Ortega of the Broken Shaker in Miami Beach say they have moved away from using St-Germain.

“It has gotten so overused that it has lost its uniqueness,” Ortega said.

“Now it’s on everybody’s drink list.”