SAN MARCOS -- Stone Brewing Co. is adding two custom-made 150-barrel fermentation vessels to its production line, but the improvements do not eliminate the company's plans to build and move to a new plant in the near future, Chief Executive Officer Greg Koch said this week.

The brewery, which has become one of the fastest-growing companies in the country, according to Forbes Magazine, plans to move its operation to a 50,000-square-foot brewery in 2005 that could eventually be expanded to about 100,000 square feet, Koch said. He added that the company, which employs 63 people, will likely outgrow its 26,500-square-foot warehouse off Rancheros Drive quickly.

"We recently added about 10,000 feet to have a little breathing room," Koch said. "Our new fermentation vessels should really help us out until we can find a site."

Koch said that he hopes to keep the company in North County but hasn't found anything to his liking quite yet. The city has pointed out several possible sites to keep the company in town.

Steve Wagner, the company's president and brewmaster, noted recently the possibility that a restaurant and a viewing platform will be included in the expansion plans so people can see the whole process.

Wagner and Koch have said that they expect the business to continue to grow, and their beers have become available in 18 states across the country, including New York, Massachusetts, Texas and Colorado.

With the continued growth, Koch has said that the company's sales are expected to rise from $6 million in 2002 to about $8.5 million this year.

But despite the increases in their distribution area, the brewery officials want to concentrate on the local market.

"Sixty percent of our business is in Southern California," Wagner said recently. "This is our home, and it's very important to us that we succeed here."

"It's definitely going to be a challenge to stay here," Koch said. "But if we can, we will. The community has always supported us, so we would hate to give that up."

The new vessels will allow the brewery to boost its annual production levels by 6,000 barrels, which equals 12,000 kegs or 186,000 gallons. Stone Brewing grew 41 percent in 2003, and projects growth of 35 percent to 40 percent in 2004.

The North County outfit, which started in 1996, mocks its customers for their lowbrow taste and prides itself on its powerfully bitter brews.

The company does not have a budget for advertising, Koch said.

"Would you buy a wine advertised on television?" Koch asked. "When you're doing something better than everyone else, word of mouth is the only advertising you need."

Koch said that his company has the reputation of being the highest-rated brewing company in the country and next year's sales, he said, are almost sure to continue to grow.

"We're very proud of our business accomplishments," he said. "The new fermentation vessels will help our growth, but when we eventually move, things will really take off. As for the future, we don't plan on moving (from San Marcos), and our goal is to stay put. Hopefully, everything turns out that way."