In Austin’s crowded and competitive bar scene, establishments continually seek the next cool thing — something to draw customers in and, ideally, keep them coming back. Swift’s Attic bar manager Jeff Hammett seems to have created a winner in his Ice Ball Cocktails. The drinks are tasty, attractive, quick to serve and half-price ($6) during happy hour.

Balls of ice are nothing new on the bar scene, of course. Spheres melt more slowly than other frozen forms, meaning straight spirits and short cocktails like an Old Fashioned stay cold longer and don’t become as diluted. Ice balls also look nice. You can make your own using molds and makers readily available on Amazon.

That’s just what Hammett was doing, putting balls of ice in his bourbon at home, when he decided to experiment. "I put everything but the main spirit in a ball and froze it, and as it melts the flavor of the drink changes. It goes from boozy to sweeter as you go."

With the help of the establishment's bartenders, he took his Old Fashioned recipe and created an ice ball version. Now called Ice Ball Oldie, it includes cherry heering, orange and lemon zest and a maraschino cherry frozen in the ice ball. Knob Creek Rye is poured over it in a glass. They next developed Strawberry Fields, with Pastry Chef Callie Speer assisting in getting the flavor just right. That one has strawberries, kaffir lime and toasted coriander sherbet in the ice ball, with Santo Azul Blanco and Prosecco poured over it. One of Hammett’s favorites is Stage Name, which uses Waterloo Barrel Reserve, an organic barrel-aged gin made in Austin, over an ice ball of sage, housemade sage syrup and lavender bitters.

Apple Mint Julep, an ice ball of mint leaves, housemade mint syrup and apple bitters with Makers, melts a bit faster, perhaps because of the leaves, creating a richer flavor sooner. A Manhattan and Sazer-rock round out the ice ball cocktail menu. Any of the cocktails can be “reloaded” with an additional shot of the same or a different liquor as the ice melts.

It took some finesse to figure out just the right amounts of each ingredient in the cocktails to ensure the ice freezes properly. Hammett uses a patented mold and mixes the ingredients just as he would for a regular cocktail. "For the Old Fashioned, or Oldie, for example, you muddle the lemon, add the bitters, add a cherry and water and freeze it," he says. "The amount of water depends on the cocktail itself."

The ice balls are made ahead of time, which he sees as one of the appeals. "That’s the beauty of it, all the prep work is done so you have a great classic cocktail as soon as the person comes in the door," he says. "Just pour a shot on top and you’re good to go."

The cocktails have proved popular and Hammett has heard that some other bars are thinking about trying them. But one Austin bartender notes that the difficulty of making the ice balls in volume will likely keep the fad from catching on. Hammett has no problem with that, and doesn’t plan to take Ice Ball Cocktails off the menu even with fall approaching.

Cocktails need to be unique to the venue, says noted bartender Francisco Santos, manager of the Rivoli Bar & Lounge at The Ritz, London, and cover all the senses: sight, hearing, touch, smell and taste. Swift’s Ice Ball cocktails have that down cold.