The year was 1981, the place Pennsylvania.

As a young Mexican exchange student, Gerardo Galván wanted to treat his American host family to an exotic delicacy from his homeland.

So he made them guacamole.

“Now avocados are everywhere, and I’m not trying to compare us with that, but this ...”

He paused to tap a fingernail on the 12-ounce glass bottle from which he’d been sipping.

“This is a big brand. It’s going to be huge. And it’s just a matter of time.”

Galván -- whose quiet, deliberate speech belies global ambitions -- has spent the last decade building a kind of accidental cult around the gentle fizz and clean flavor of a Mexican mineral water called Topo Chico.

He’s the general manager of Fort Worth-based Interex Corp., which essentially serves as Topo Chico’s presence in the United States. On a recent afternoon, Galván sank into a couch at his home in a tony Coppell subdivision discussing how one of the Lone Star State’s most coveted brands came to be.

Though Mexicans have been drinking Topo Chico (named for the Monterrey neighborhood where it’s bottled) since 1895, the number of Texans who swear by it has continued to climb in recent years.

Scroll through Instagram and you might see the green-tinted bottle, with its yellow label and vintage red logo, adding a pop of color to shots of espresso bathed in golden light.

In Austin, mixologists use splashes of Topo Chico to round out cocktails. It’s the only sparkling mineral water sold at Dallas’ Winspear Opera House.

Last summer, even The New York Times "discovered" Topo Chico.

All that points to the brand’s unique position at the nexus of major market forces -- from the North American Free Trade Agreement to the premium water boom. Which, in turn, makes Topo Chico poised to explode nationwide, experts say.

1 / 5Gerardo Galvan, general manager of Mexican beverage manufacturing and distribution company Arca Continentalon, poses for a portrait with a bottle of Topo Chico on Friday, January 20, 2017 at his home in Coppell, Texas. Galvan is credited for bringing the carbonated water drink to Texas. (Ashley Landis/The Dallas Morning News)(Staff Photographer) 2 / 5Pallets of Topo Chico are ready for distribution at Taxco Produce, Inc. in Dallas, photographed on Wednesday, January 25, 2017. (Louis DeLuca/The Dallas Morning News)(Staff Photographer) 3 / 5Topo Chico Mineral Water was established in 1895. The water is bottled in Monterrey, Mexico. Bottles were photographed in The Dallas Morning News photography studio in downtown Dallas Wednesday February 1, 2017. (Andy Jacobsohn/The Dallas Morning News)(Staff Photographer) 4 / 5Pallets of Topo Chico are ready for distribution at Taxco Produce, Inc. in Dallas, photographed on Wednesday, January 25, 2017. (Louis DeLuca/The Dallas Morning News)(Staff Photographer) 5 / 5Topo Chico Mineral Water was established in 1895. The water is bottled in Monterrey, Mexico. Bottles were photographed in The Dallas Morning News photography studio in downtown Dallas Wednesday February 1, 2017. (Andy Jacobsohn/The Dallas Morning News)(Staff Photographer)

"What's amazing is that your Topo Chicos and your Sparkling Ices, your LaCroix -- they've been around forever, but that's just the rising tide in the category right now," said Jeffrey Klineman, editor in chief of BevNet, an industry publication that tracks beverage trends. "If it's a brand that's very popular in Texas, you've got growing [demand] and growing [consumer numbers]. ... It's more capable of making a national push than it has been in the past."

Despite its newfound cachet, the story of Topo Chico in the U.S. actually begins with Coca-Cola, Galván said.

Topo Chico’s parent company, now known as Arca Continental, was the first to bottle Coke outside the States through a deal struck in the 1920s.

Galván remembered that in company lore, Coke in Mexico was marketed as being made with Topo Chico water.

“So we can say that Topo Chico was the beginning of this huge Coca-Cola group in Mexico,” he said.

Over the decades that followed, as Texas’ Hispanic population increased, the movement reversed: Bottles of Topo Chico found their way over the border with natives of northern Mexico, who craved a taste of home.

Galván said that when NAFTA was negotiated in the late 1980s, the company’s bosses at the time saw an opportunity.

“Before that, there was Topo Chico in the U.S., but somebody else was doing the business,” he said. “This was more like, let’s give the company a formal shape and sales reps to start selling the product.”

Galván didn’t get involved with Topo Chico until later; NAFTA was a hot topic of discussion while he was in school.

But the trade deal, which economists credit with building the free flow of products and money between Texas and Mexico, paved the way for Galván and his team today, he said.

After working for Coca-Cola, Galván was hired by Arca Continental. In 2003, he was sent to Texas to spread the good word on Topo Chico, and he’s lived in the Dallas area ever since.

The way Galván sees it, Topo Chico’s rise in Texas has had three phases. The first one was from the late 1980s to about 2000.

“The first 10 years we were more into the Hispanic consumer that was demanding the brand because they liked a nostalgic thing,” he said.

From 2000 to 2013, “we developed different strategies and launched different packages.”

Then, a few years ago, trends shifted toward healthier and natural products, away from soda.

And although Topo Chico had been present at events catering to the Latino community, like soccer games, the company started adjusting its strategy.

“In 2013, we realized that Topo Chico has huge potential,” Galván said. “We started going to Lollapalooza in Chicago and Austin City Limits, fashion shows ... la creme de la creme.”

Topo Chico had found its way into a coveted consumer niche.

Now, you’re as likely to spot Topo Chico on the menu at a trendy $5-coffee shop as in the drink case at the local taqueria.

Galván estimated that Topo Chico’s U.S. sales have multiplied by 15 since 2000. Last year, he estimated, the company sold about 240 million bottles of the stuff. Interex -- which also distributes a few other products -- generates about $80 million in annual revenue.

As for that other Instagrammable resurgent sparkling water brand, LaCroix Sparkling Water? Galván doesn't consider it competition.

"You need to watch the game you're playing."

“It’s in the same segment of carbonated water, but we like to split the category,” he said. “You need to watch the game you’re playing.”

San Pellegrino, Perrier and Acqua Panna, he said, are in a higher price bracket. That’s where Topo Chico plays.

Klineman, of BevNet, said that’s a smart tactic.

“Everybody’s got to have a point of differentiation, so in saying, ‘We’re Mexico’s Perrier,’ you’re selling against products that actually haven’t been growing as fast as things like LaCroix and Sparkling Ice,” he said. “Topo Chico is absolutely growing faster than any other kind of imported sparkling water brand.”

According to data from IRI, compiled by BevNet, sparkling water’s dollar sales increased more than 16 percent over the year that ended in November.

During that time, Topo Chico’s sales grew 27 percent to about $63.5 million -- though Klineman cautioned the IRI data may be incomplete, especially for measuring sales of a regional brand.

The data from IRI lists Florida-based National Beverage Corp.’s original LaCroix Sparkling Water line as having raked in more than $234 million over that year, making for a dollar sales growth rate of 65 percent.

Perrier took in almost $227 million, growing about 17 percent, while San Pellegrino sold just over $127 million worth of bubbly water and grew just 11 percent.

Luisa del Rosal, executive director of SMU’s Mission Foods Texas-Mexico Center, said Topo Chico’s success in capturing a wealthier consumer base also means that the brand will be better insulated from any reversals in international trade policy.

In other words, if NAFTA went away tomorrow, Galván said, he thinks Topo Chico buyers would be willing to pay the extra 5 cents or so for a bottle, because price isn’t their primary driver.

Del Rosal said that offers a lesson for smaller Mexican exporters who can capitalize on a growing segment of American consumers willing to pay more for natural foods and handmade products.

And today, it’s easier than ever to access those buyers.

“There’s still a great need for indigenous people in Mexico that make beautiful products,” she said. “They’re expensive, but to certain consumers, it’s worth it.”

More broadly, though, President Donald Trump’s vows to upend trade policy with the United States’ southern neighbor would almost certainly make imported products, including Topo Chico, more expensive. And, Del Rosal said, Mexico’s economy overall would take a big hit.

Nevertheless, Topo Chico's popularity stateside shows just how deeply intertwined Texas' and Mexico's cultures have become -- and how much of that stems from the NAFTA-led integration of the two economies.

“Topo Chico and Mission Foods are not just Mexican, they’re not just Latino,” she said. “They’re Texan.”

Alfredo Duarte, president and co-founder of Taxco Produce Inc., has seen the shift firsthand.

His business -- which distributes mostly Mexican fruits, vegetables and foods to restaurants and stores around the region -- has grown from what was essentially a stall at the Dallas Farmers Market to a warehouse and office that takes in truckloads of stuff every day.

As one of Galván’s first Topo Chico distributors in Dallas, he said he’s seen demand for the agua mineral skyrocket.

“I met [Galván] 20 years ago, and oh my god, we started at half a pallet [of Topo Chico] every week to truckloads now,” he said. “That is crazy -- we’re talking ... 30,000 to 40,000 cases this year, and that’s just one small company.”

In the end, Galván said, Topo Chico’s basic grassroots marketing has powered its growth -- well, that, and a product he believes is really that good.

He once sent a handful of bottles home with his son’s math tutor, who was curious about the house beverage. The tutor came back to say that his wife was addicted.

Galván said the company’s 20 or so employees -- five of whom are based in Fort Worth, with the rest fanned out across the U.S. -- text message each other when they notice that a store doesn’t carry Topo Chico or they spot a potential partnership.

“If you’re in California or Chicago or even if you live here in Dallas, you won’t hear any Topo Chico advertisements on the radio or on TV,” Galván said. “We’re trying to use all of our budget to go be at the store level ... somebody tastes it, then they get hooked.”

Galván said Interex expects to grow and to hire as the company makes its fizzy envoy more widely available in markets around the country.

San Francisco looks good, he said. So does New York.