Today, we know Mountain Dew as a hyper-bright, supercharged sugary soft drink contained in a bold green can with an aggressive font. It’s marketed as the nectar of extreme sports and considered the liquid of choice among young, underaged children in need of a faux-electric jolt. But long before Mountain Dew was a highly caffeinated soda beloved by rowdy kids, it was a mixing elixir for adults specifically designed to improve the taste of whiskey.

Granted, it wasn’t the same beverage back then as we know it today, but discovering the soda’s old- school connection to alcohol still packs a delightfully stunning surprise. How it evolved from a mixer to the liquid equivalent of a pop-punk anthem is a story of dogged perseverance, innovative marketing, and slight mystery.

The Roots of Mountain Dew

Like most things relating to alcohol, the details behind how Mountain Dew came to be are a bit muddled. The beverage’s roots were either planted in the late 1930s or the 1940s, depending on the source. Beverage industry professionals and brothers Barney and Ally Hartman moved to Knoxville, Tenn., in 1932, after the Augusta, Ga-based Orange Crush bottling plant they worked at shuttered. The brothers realized a problem once they settled: Their favorite whiskey mixer, a lemon-lime (and long since defunct) soda called Natural Set-Up, wasn’t available in Tennessee — a common issue back in the 1930s, when most sodas were hyper-regionalized.

Get the latest in beer, wine, and cocktail culture sent straight to your inbox.

Rather than making the roughly 300-mile journey back to Augusta to load up on the beverage, they decided to work on creating their own version. Eventually, they developed a similar clear-colored, caffeine-free, lemon-lime mixer that improved the taste of the whiskey they drank, giving it a moonshine-like quality. Considering Tennessee didn’t repeal Prohibition on the state level until 1939 — the first year many American distilleries finally brought their first round of post-Prohibition bonded whiskeys to market — it seems fair to speculate that what the brothers were drinking was likely homemade hooch that needed some help in the flavor department, à la bathtub gin.

After years of making the mixer for themselves, their family, and a few industry friends, the Hartmans decided to try bringing their product to the masses. They named their creation Mountain Dew, and with good reason: The term was a popular slang term for moonshine — popular enough to be immortalized in the Appalachian folk song “Mountain Dew,” a tune whose own lyrical roots trace to the year 1928. However, the Hartmans’ soda-based mixer floundered on the market, and an ambitious pitch to partner with Coca-Cola fell flat.

In 1946, the brothers hatched a different approach to marketing their product, playing down its status as a whiskey mixer and repositioning it as a refreshing Appalachian soda, complete with hillbilly mascots like “Willy the Hillbilly” and deliberately misspelled slogans like “It’ll tickle yore innards.” Barney died of a heart attack in 1949, but Ally continued to promote the product in the hopes it would grow. His persistence paid off: In 1958, the rights to Mountain Dew were purchased by the Tip Corporation, a beverage company in Marion, Va. According to legend, Ally offered the rights to the recipe to Tip’s president, Bill Jones, for free in memory of his late brother. Jones refused this gesture, and instead offered to pick up the check for the dinner they were having in exchange for the recipe — a purchase that cost Jones just $6.95.

A Bold Transformation

Mountain Dew’s acquisition by the Tip Corporation sowed the seeds of the modern product, but there’s ongoing debate on who, exactly, were the sowers. Some reports claim Jones tweaked the formula to bring out its citrus notes. Others say the beverage’s original formula was replaced outright with another product called Tri-City Lemonade but kept the labeling and marketing intact. Regardless, this new version of Mountain Dew attracted the Pepsi Cola Company, which purchased the soda’s rights in 1964. Pepsi kept the brand’s stereotypical hillbilly packaging intact, which made sense considering that popular television shows at the time like “The Beverly Hillbillies,” “Petticoat Junction,” and “Green Acres” tapped into a similar cornpone zeitgeist.

Pepsi ditched the beverage’s bumpkin branding in 1969 to court a younger market, but it wasn’t quite done transforming the Dew. In 1974, Pepsi infamously added the food dye Yellow 5 to the mix to give it its infamous near-neon hue. What color it is depends on the person drinking the beverage: Some people call it yellow, while others insist it’s green. Mountain Dew itself tends to be mum on the subject.

A Return to Its Roots

Things are cyclical in the beverage industry. Bourbon’s ongoing renaissance happened after decades of category dormancy. Pre-Prohibition cocktails like the Corpse Reviver No. 2 and Last Word were obscure relics from a bygone era before they suddenly returned to relevance. It turns out that Mountain Dew is no different.

Last year, the punchy pop found its way back into the good graces of metropolitan imbibers with the Mountain Suze, a two-ingredient highball consisting of Mountain Dew and Suze, the bitter, herbaceous French aperitif made from gentian root. Sother Teague, acclaimed bartender and beverage director of Amor y Amargo in New York’s East Village, thrust the drink into the world via an Instagram video after a friend came up with the name at a backyard barbecue. He was shocked by its deliciousness — his “holy shit” vocal response in the video confirms this surprise — but he also understands why it works, even if he doesn’t place it in a traditional cocktail category. “It’s more of a ‘high-low’ than it is a highball because of the ingredients,” he explains. “You got this lofty, sophisticated, bitter ingredient with Suze, and then you pair it with this lowbrow, sugary-sweet drink that’s almost for kids. It ends up working well in a weird mixology way.”

Other than being shockingly delicious, the Mountain Suze does something remarkable. The beverage ends up tapping into Mountain Dew’s original roots, back when its main intention was to mix it with a spirit and create something simple and easy-drinking. As such, the Mountain Suze is best served in settings that match this vibe. “Would I ever serve it at my bar? Probably not,” Teague says. “But if someone offers it to me after I’ve been mowing the lawn all day? Hell yes, I’m drinking it.”

Everything Old Is New Again

If you’re not into bitter aperitifs, don’t fret: Suze is no longer needed to experience Mountain Dew in its former glory. In February, PepsiCo. and Boston Beer Company officially jumped into the RTD game with the launch of “HARD MTN DEW,” a 5 percent ABV canned version of Mountain Dew’s original black cherry, watermelon, and Baja Blast flavors. These beverages, which will roll out into other, undisclosed (for now) states beyond their initial launch in Florida, Iowa, and (appropriately enough) Tennessee later this year, are bound to elicit over-the-top social media reactions from Mountain Dew die-hards that may or may not be written in all caps.

But they’re also oddly symbolic of where Mountain Dew came from, even if they don’t quite taste like the soda did way back when. HARD MTN DEW may carry the appearance of a soft drink taken to the extreme. However, it’s worth noting that the brand itself was invented almost by necessity as a spirit-salvaging elixir in a state that clung to Prohibition several years after the 21st Amendment passed. Viewed in that light, one could argue that taking things to the extreme has been part of the Mountain Dew ethos from day one.