Leave it to Dave Arnold to solve a cocktail problem using as much science-minded equipment as possible. Better hot drinks? Optimized dilution? Amped-up citrus? Check, check and check.

So when it came to hacking highballs at his New York bar Booker and Dax and, later, Existing Conditions (both now closed), Arnold devised an elaborate carbonation rig to keep bubbles from going flat: Cocktails were pre-batched, individually bottled and chilled in a cold-water bath. When it was time to serve a drink, the bottle would be carbonated à la minute via a hose connected to a CO2 canister, then poured into an iced Collins glass, finished with a spritz of fresh citrus juice halfway through the pour.

When Garret Richard, who worked alongside Arnold at Existing Conditions from 2018 until it closed in 2020, built the bar program at Sunken Harbor Club, the tropical bar above Brooklyn’s Gage & Tollner, he brought along Arnold’s carbonation process. 

“It’s a big part of the program at Sunken Harbor,” says Richard. But for anyone making drinks at home, “it’s a big ask.” So he devised an alternative, home bar–friendly, method to include in his new book, Tropical Standard, to optimize effervescence for his Kingston Zing, a riff on Jamaica’s beloved Wray & Ting. The method works for other highballs, too. Even a simple two-ingredient drink like a Gin & Tonic can benefit from this technique, he says, and no special equipment is necessary.

Here are Richard’s step-by-step tips for building a better, bubblier highball:

1. Spirits and glassware need to be as cold as possible.

Store both in the freezer. “The cold spirit prevents the ice from weeping water,” Richard explains. “You want to minimize dilution from the ice as much as possible,” he adds, in turn preserving effervescence in the mixer. 

Meanwhile, the cold glassware encourages more even distribution of CO2 (carbon dioxide) throughout the drink. “As soda water heats up, the gas will escape faster,” Richard says. “The bubbles will pop off more quickly and start to flatten in a room-temperature drink.”

2. Briefly stir all of the ingredients besides the soda.

This step can be skipped for two-ingredient highballs, but in the Kingston Zing, for example, Richard combines the rum, grapefruit punch syrup, strained lime juice, grapefruit bitters and a few drops of salt solution in a cocktail tin. That mixture is quickly blitzed with a hand-held milk frother, although a brisk turn with a small whisk or bar spoon would do the trick too. In a pinch, a dry shake (without ice) will work, but Richard prefers stirring to shaking for this step.

Integrating the ingredients before the soda (or other bubbly mixer) is added means minimal stirring later. “The more you move the soda around, you’re going to start flattening it,” Richard warns.

3. Split the soda.

Richard adds the ingredients to the chilled highball glass in a very specific order: first the ice, then the rum, followed by about three-quarters of the soda. Next, he pours in the contents of the mixing tin. Last, the drink is topped up with the remaining soda water. 

“That little move of pouring the carbonated drink and [then] halfway through adding lemon or lime, then topping up—that’s inspired by how we did carbonated drinks at Existing Conditions,” explains Richard. “The bubbles will do a lot of the work of distributing the ingredients in the cocktail.” It also minimizes the need to stir, meaning the carbonation will stay crisp for longer.

Even a simple G&T or classic whiskey highball can benefit from this build: Fill a chilled glass with ice, then pour most of the tonic or soda water in, followed by the chilled spirit. Then top up with the remaining tonic.

4. Finish with a quick dip of the bar spoon.

“It’s just a spot check,” Richard explains. “It can be just a quick up-and-down [move] in case you didn’t fully integrate everything.” While it’s useful for highballs with more viscous ingredients, like syrups, this step can be skipped if, say, just a squeeze of citrus is added to the spirit-soda combo.

Though the highball tends to be one of the most laid-back drinks, “it’s sometimes treated too casually,” says Richard. Just a few small changes—like the order in which the ingredients are added—can have a big payoff in the quality of the drink.

“Treat the soda, the carbonation, with respect, and know there’s a time clock on it,” he says. “Just knowing a couple of the rules of the road makes the drink better.”