On a Friday night last May, between snapping selfies in their rhinestone-encrusted outfits and belting out the words to “Cruel Summer,” Taylor Swift fans dashed from their seats at Gillette Stadium in search of refreshments. At the concession stand of the Foxborough, Mass., venue, thousands of concertgoers ordered Lavender Haze, a vodka-and-fruit-juice cocktail named for a track off Swift’s 2022 “Midnights” album. The drink - bedazzled with edible purple glitter - sold to the tune of 8,000 per hour.

Had the drinks been individually made, it would have taken a small army of hundreds of bartenders to fulfill those orders. Doing so quickly enough that fans wouldn’t miss the next song would have been impossible.

“You can’t do that. You don’t want to do that,” said Tiffanie Barriere, an Atlanta-based spirits and cocktail educator and consultant who has been a celebrated bartender for more than a decade.

But those Lavender Haze cocktails weren’t shaken or stirred - they were poured straight from a keg, no differently than a beer would be. Concession stands could serve them rapidly, ensuring fans didn’t wait in long lines. The fact that Swifties could order a themed drink in such volume speaks to the growing ubiquity of kegged cocktails, which are hitting draft lines everywhere from sports stadiums to corner bars. Barriere loves the process of shaking delicious, fresh drinks for guests, but she doesn’t turn her nose up at the new wave of draft cocktails.

“Of course you’re not seeing someone grab a lemon to make your cocktail, but there’s lemon juice or citric acid in there. It’s not the freshest, but the quality can still be there,” she said. “It still makes a great cocktail.”

Draft cocktails have existed for roughly a decade, but they’re seizing an opportunity this year as kegged beer sales have declined. U.S. on-tap beer volumes fell about 5 percent year over year in 2023, according to government data, continuing a years-long trend that began even before the coronavirus pandemic temporarily closed bars and restaurants. In 2018, draft beer made up about 11 percent of overall beer volumes sold in the U.S., according to industry data compiled by Beer Marketer’s Insights; last year, it was 9 percent. And bar owners have been happy to swap out slower-moving beers on draft lines for cocktails. Where there were fewer than 1,500 draft lines in the U.S. dedicated to non-beer products before the pandemic, there are now roughly 10,000, according to Draftline Data, which provides data and analytics for beer distributors.

“With the decline in draft beer, that’s going to give [bar owners] more opportunities to make that switch, as draft cocktails become more normalized,” says Gareth Croke, co-owner of D.C.-area bars and restaurants Boundary Stone and All-Purpose, which serves some cocktails on draft. “The trend is most certainly going in the direction where a larger selection of beer is not necessarily better.”

What’s flowing through tap lines mirrors what’s happening in alcohol broadly. Americans are drinking more servings of spirits today than in decades past, at the expense of beer and wine. To meet that demand, venues are turning to kegged cocktails as an efficient way to deliver consistent drinks, fast. They’re aided by new technology: The past three years have seen the launch of premade kegged cocktails - some with alcohol, some with just mixers to which bartenders add spirits of their choosing. Bars and restaurants can also make draft cocktails themselves, based on custom recipes.

“Maybe you’re selling canned or bottled beer but also offering a margarita on draft through those beer lines,” said Dan Butler, general manager of Petco Park, the home of Major League Baseball’s San Diego Padres. “With the increase in attendance we’ve seen and wanting to increase speed of service, going to draft cocktails made sense.”

Last year, Petco Park began working with Craft Standard, which sells kegs pre-filled with cocktail mixers to which the venue adds spirits. Before that, cocktails from the stadium’s concession stands were made to order. Butler said that when Major League Baseball introduced its pitch clock last spring to speed up games, faster-to-serve draft cocktails were an important upgrade. Now, attendees have more cocktail options - such as an Aperol ruby spritz, rum punch or Cadillac margarita with Grand Marnier - served to them more quickly.

This is also the raison d’être behind Halfday, the brand that makes the Lavender Haze cocktail for some stops on Taylor Swift’s Eras Tour. Its kegs are fully ready-to-serve, with alcohol and juices included. Both Halfday and Craft Standard kegs attach to existing draft beer systems, with no special equipment or adjustments required. That’s helped bring cocktails to bars that previously would have served cocktails only in limited VIP areas or in cans.

“Draft cocktails allow something to be possible that wasn’t possible before,” said Chase Brooks, founder of Halfday. “Someone’s looking at a menu and saying, ‘Oh my god, I’m at a Taylor Swift show and I can have a margarita?'”

But kegged cocktails aren’t only for stadiums. Portland, Ore., cocktail bars Dirty Pretty and Pink Rabbit collectively serve eight kegged cocktails, which beverage director Ben Purvis said not only speeds up service but can allow for more precise recipes. How much water ends up in an Old-Fashioned, for example, can vary based on the size of the ice cube and how vigorously a bartender stirs. Batching and kegging an Old-Fashioned means Purvis can dial in the dilution for every drink. He’s considering reducing the number of draft beers at Pink Rabbit to make way for even more kegged cocktails.

Patrons don’t seem to mind whether their next drink comes from a shaker or a spout. Neither bar’s menu identifies which cocktails are kegged and which are made-to-order, and Purvis said customers can’t distinguish a difference in quality.

“Our taps are right out front on display at Dirty Pretty, and we’ve never had a negative customer interaction about finding out a cocktail was on a keg,” Purvis said.

Brooks is bullish on what kegged cocktails can do to bring in-demand, liquor-based drinks to more bars and large venues. Unlike shaken or stirred drinks, kegged cocktails don’t require highly trained bartenders. Anyone who can pour a draft beer can also pour a draft margarita, often saving owners money on skilled labor.

“We have been grossly underestimating just how big the cocktail movement can be as a result of them being fundamentally difficult to access in many places,” Brooks said, noting that 80 percent of the time, a Halfday draft line replaces one that had previously poured beer. “What is incredible to watch is how many people don’t have a Bud Light in their hands because they have a margarita in their hands.”