As the beer industry descended on Denver for the Great American Beer Festival, signs of the craft beer boom were all around.
In attendance were more than 630 breweries, the lucky ones able to quickly snag a spot before registration closed in just an hour and 40 minutes. Hundreds more breweries were on the wait list.
The brewers in Denver represented just a portion of the more than 2,500 breweries operating in the United States—the most since Prohibition. What's more, there are 1,500 other breweries in the planning stage.
With all the growth, many in the craft beer industry attending the festival frequently turned to the same question: How far can the craft boom go?
"I think at one point it will look like the restaurant industry, with a lot of small players entering and exiting," said Bart Watson, an economist with the Brewers Association. "That said, at this point, there is ... evidence that supply still isn't meeting demand."
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Take this: The Brewers Association reported mid-year 2013 growth of 15 percent in dollar sales and 13 percent in volume for craft beer. If these trends hold up, it will mark the fourth-straight year of double-digit growth.
Looking to meet that demand, many established players like Sierra Nevada Brewing and Lagunitas Brewing are among a growing number of craft brewers expanding to increase capacity.
But while larger brewers bulk up to meet national demand, Watson said he expects the craft brewing future to be an increased number of smaller breweries serving local needs, like in Europe.
"Germany has a lot more breweries per capita than the United States," he said. "If the U.S. had the same number of breweries per capita as Germany, we'd have about 5,000 breweries."
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While that number sounds lofty, Samuel Adams founder and Boston Beer Chairman Jim Koch isn't one to shy away from big expectations. He still sees plenty of room to run.
"Each day there are more drinkers demanding craft beer, retailers making more room on the shelves and bars adding more tap handles. I think there is room for two or three, or maybe even 4,000 more craft breweries," Koch said.
As the number of entrants into the beer business increases, the craft industry is starting to draw comparisons to another crowded alcohol segment: wine.
"There are over 7,000 wineries in the country right now, and that's in an industry that is outsold by beer in terms of dollars and volume," Watson continued. "So there's clearly room for growth in the beer industry, with small breweries that are serving local markets."
A key metric to watch is the gap between the number of brewery openings and closings, he said.
"Right now openings are far exceeding closings in both microbreweries and brew pubs. But at a certain point, in a mature market, you're getting a similar number of entrance and exits," Watson said. "We're clearly not there yet, but 20-25 years down the line, we may reach a point where we see those numbers evening out."
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As for Samuel Adams' Koch, he sees the increased competition as a positive.
"The craft beer market today is hyper competitive. There are breweries opening somewhere in America every day, and to me that's good," he said. "Competition makes you strive to improve everything you do and to innovate and push the envelope to make better beer. I think that's a great thing."
—By CNBC's Tom Rotunno. Follow him on Twitter @TomRotunno.