According to Eloise Bryan, J.P.’s granddaughter and the hotel’s concierge and marketing director, they’ve been serving the drink for more than a decade. “The origin is fuzzy, and I’ve never heard a true origin story,” she says, noting that they do not claim to have invented it. “But it’s likely we are one of the first places to serve it.” Punch Drink pegs its menu placement to 2010. It’s important to note that was the same year that Gage Hotel hired Williamson to redo its kitchen and bar menu.

Bryan agrees the drink likely existed before it ever graced a menu. Margaritas rule the state, and Topo Chico—produced in Monterrey, Mexico since 1895—had been available to in-the-know Texans for decades. So, it’s possible that it sprung up naturally, the product of thirsty locals and home bartenders. 

Despite the drink’s history, which clearly spans more than two decades, it took a while to reach its current phenomenon status.

“It’s my job to know tequila trends, and this Ranch Water thing caught people by storm only in the last few years,” says Alan. “Ranch 616 has the most obvious paternity case. It was pounded at this one restaurant in Austin for at least 10 to 15 years before anyone else cared about it.” Now, people care. “To me, it’s a margarita with a Topo on the side. As you drink the Marg, you top it with Topo so the drink changes. That’s how it started.” 

But that’s not how it’s typically served today. In Ranch Water-swilling cities like Dallas and Houston, you may see the drink served tall over ice, with the water mixed in. Or it may come straight in the Topo Chico bottle, with a couple ounces of water dumped out and tequila and lime juice poured in. Orange liqueur is rarely present, though Topo Chico is still the go-to choice for sparkling water.

“It’s flattering that this phenomenon has taken off,” Williamson says. “It’s on every menu in Austin, Dallas, and Houston.” But no one’s sold more of the refreshing drink than Ranch 616. “According to my accountant, since opening we’ve sold $18 million worth of Ranch Waters.”