When Sweetwater Brewing Co. partners Freddy Bensch and Kevin McNerney realized that it was time to expand again, they decided to do it in a dramatic way.

In late March, they tore the roof off part of their brewery and had eight towering, 400-barrel fermentation tanks installed with a crane.

Bob Townsend/Special (ENLARGE)

Sweetwater partners Freddy Bensch (left) and Kevin McNerney had to tear the roof off the brewery to install eight new fermentation tanks.

SWEETWATER BREWERY • Tours 5:30-7:30 p.m. Wednesdays, Thursdays, Fridays. 195 Ottley Drive, Atlanta. 404-691-2537, www.sweetwaterbrew.com BOB TOWNSEND BEER PICK E-mail Townsend Related: • More on food and drink • Restaurant reviews and search More Townsend The pour, and more, rock his world  Terrapin Roggenrauchbier, Terrapin Beer Co.  Why drink locally made beers? They're the freshest  Dogfish Head Immort Ale  Brew, food, wine: What's not to like?  • Bob Townsend is editor of Southern Brew News, a bimonthly beer publication distributed throughout the Southeast.

The move will double Sweetwater's capacity, letting the company keep up with demand for its wildly popular flagship beer, Sweetwater 420, while giving its brewers more opportunity to experiment.

"We were pretty much maxed out," McNerney said.

"It's going to release the pressure, as far as day-to-day beers," Bensch said. "And it allows us to broaden our horizons in terms of new styles and new flavors. We can have some fun now, rather than just making the same widget every day."

In 1997, Bensch and McNerney opened their first brewery in a west Fulton County industrial park, near Sweetwater Creek. In 2002, after winning multiple awards for its beers, Sweetwater was voted Small Brewery of the Year at the Great American Beer Festival, and McNerney was voted Small Brewery Brewmaster of the Year.

In 2004, the partners moved the brewery closer to downtown, building the current, bigger and better facility on Ottley Drive in the Armour Circle area.

"From the first tank that we received in 1996, when we started piecing our brewery together, every phase of expansion has been exciting," McNerney said. "But this one is exceptionally exciting because of the magnitude. It's doubling our fermentation capacity, and in essence doubling the potential output of this brewery."

To chart Sweetwater's phenomenal growth over a decade-plus in business, consider that in the first year of operation, the brewery turned out only about 1,700 barrels of beer (a barrel of draft beer holds 31 U.S. gallons). Since then, growth has been a steady 25 percent to 35 percent yearly, topping out at 37 percent last year, going from 33,000 to 45,000 barrels. With the new tanks, which will bring capacity to 110,000 barrels, Sweetwater is poised to become the largest craft brewery in the Southeast. Right now, Sweetwater ranks 30th among the top 50 American craft brewing companies (Boston Beer Co. is No. 1) and 43rd among the top 50 American breweries overall (Anheuser-Busch is No.1).

Sweetwater's success continues to track the success of the American craft beer market, which once again grew by double digits in 2007, leading all other segments in the beer category. The Boulder, Colo.-based Brewers Association reports that sales by independent craft brewers were up 12 percent by volume and 16 percent in dollars for 2007.

"Just as these big tanks are a kind of mark of Sweetwater's success," McNerney said, "they're also kind of a mark of the craft brewing segment as a whole. These little mom and pop microbreweries aren't so little anymore. I think Sweetwater is a very good gauge of that."

Sweetwater is sold in six states in the Southeast, with major markets in Greenville, S.C.; Asheville N.C.; Nashville, Knoxville and Chattanooga; Birmingham; and several areas of Florida and Georgia. But Atlanta remains the biggest by far. And Bensch and McNerney say they want to continue to be known as a local brewery.

"The other thing that's exciting is to know that Atlanta has embraced us, and we've captured the attention of so many people in our local market," McNerney said.

"Bigger is not necessarily better," Bensch said. "More than numbers and figures, it's about who's doing it and how it's getting done. That's what matters to me. This is not a big corporation.

"I was back in the brewery today, getting dirty and bloody. But it's fun. We are still doing what we like to do. That's why I'm still here, 11 years later."