There’s nothing flat about hard seltzer. In fact, sales of the low alcohol, low carb, low sugar style of fermented beverage are positively fizzy, with a Nielsen report stating that sales of the beverage were up 193 percent this summer. Naturally, the boom has inspired brewers in Colorado and beyond to try their hands at turning sugar water into something effervescent and flavorful.

In late May, Upslope released Spiked Snowmelt, a canned seltzer brand enhanced by ingredients like tangerine and hops; by the end of June, the brewery sold 5,000 cases and began offering the libations on tap. Other big beer makers that entered the arena this year include Oskar Blues Brewery with Wild Basin Boozy Sparkling Water, Anheuser-Busch with Henry’s Hard Sparkling Water, and Miller-Coors with Cape Line Canned Sparkling Cocktails.

Why are brewers so eager to take advantage of the trend? One reason: Making hard seltzer is doable. While crafting wine, cider, and spirits is not permissible with a brewers license, hard seltzers are brewed beverages, like beer. But instead of relying on grain, hops, and yeast for fermentation, the artisans use cane sugar and yeast. “It’s a great opportunity to use the equipment and the brewery. It drops nicely into the program,” says Henry Wood, head of sales and marketing for Boulder’s Upslope Brewing.

Andy Jessen, the co-founder of Bonfire Brewing in Eagle, says when big Colorado companies like Oskar Blues and Upslope started experimenting with spiked seltzer, “that signaled to the rest of us to start playing with it.”

Bonfire Brewing is always hunting for ways to appeal to people who don’t like beer, want to steer clear of gluten, or seek low-alcohol, low-calorie beverages, so the team started playing with five-gallon batches. Six months later, in June of this year, it began serving kegs of citrus, pineapple, and raspberry hard seltzers in the tap room, which were an immediate hit.

It helps the bottom line, too, since Jessen says the ability for grocery stores to now carry all kinds of beer—not just 3.2 ABV suds—has hurt sales at smaller breweries like Bonfire.

“White Claw [the blockbuster hard seltzer made by the same company behind Mike’s Hard Lemonade] could be bigger in the next few years than Bud Light,” says Charlie Berger, the co-founder of Denver Beer Co, which recently launched the brand Out & About. “That is a testament to how important it is, regardless of whether or not a craft brewer loves making it. If you are sitting on the sidelines and something this big comes along, it’s a missed opportunity.”

In July, the owners of Grand lake Brewing decided to switch gears, closing their beer production facility in Grand Lake and Grand Lake Brewing Tavern in Arvada. In place of the tavern, Hunter and Warren Wood opened the first seltzer taproom in the country: Elvtd at 5280 pours flavors like blueberry, lemon-lime, and piña colada.

Further evidence that the sparkling craze is real: Denver will host the first-ever festival dedicated to hard seltzer—Fizz Fight—on September 14 at the EXDO Event Center. For a cool $33.45, you can taste more than 20 varieties. Sound like a refreshing way to bid farewell to summer? Get your tickets here.­­