Sweetwater is growing, again.

But this time, the company that’s become synonymous with Atlanta craft beer has embarked on an ambitious expansion project that will create the capacity to compete with some of the country’s biggest breweries.

Sweetwater now ranks No. 27 among the top 50 U.S. craft brewing companies and No. 38 overall (Anheuser-Busch InBev is No. 1).

Recently, Sweetwater brewmaster Mark Medlin oversaw the installation of a centrifugal separator -- a half-million-dollar piece of equipment that will help speed the process of getting beer from the fermentation tanks to the bottling line and make production a bit less hectic during the coming months of construction.

At the brewery one recent afternoon, Medlin and Sweetwater “Minister of Propaganda” Steve Farace led visitors on a tour of the planned expansion, illustrated with an architect’s drawing and buoyed by samples of the latest Dank Tank creation, Browneyed Buckeye Brown India Pale Ale.

“We were behind on this beer,” Medlin said, “but basically, we were able to package it a few hours after it was centrifuged.”

A new building -- which will include a new bottling line and packaging hall, lab, offices, event space and outdoor deck -- will connect the existing brewery with a warehouse building next door that will house raw materials, finished goods and shipping and receiving. After that, the old bottling line will be scrapped and replaced by a new group of 1,000 barrel fermenters and bright beer tanks.

Construction is scheduled to be completed in November. But most exciting for beer geeks, Sweetwater has already been experimenting with bottle conditioning, a traditional method of naturally carbonating beer by adding a small amount of fermentable sugar and yeast to the bottle.

“We already have most of the equipment,” Medlin said. “And so far, we’ve been very pleased with our trial results. We’ve shown that bottle conditioning is hands down better beer over time. It’s going to improve the quality of our beer immensely.”

Medlin said he thinks the first Sweetwater bottle-conditioned beers may be ready by April 2012.

Later in 2012, Sweetwater will add a new 250-barrel brewhouse, with the capacity to produce up to 500,000 barrels of beer a year. Current production is on track to top out at more than 100,000 barrels in 2011. And that's what pushed expansion plans forward sooner than expected.

“It will be the first time ever that we will really have the capacity to grow as a brewery,” Farace said. “The sales are always there, then production will jump up a little, but sales always catch up and push production again.

“This kind of growth and this kind of investment in the brewery in infrastructure and the quality of equipment, these are things we’ve wanted and needed for so long. But it’s really amazing how fast we’ve been growing, especially this year. The best part is that most of our business is right here in metro Atlanta. The more beer we can sell in our backyard, the better.”