Correction

This column should have listed the address of a Web site mentioned as www.followyourfolly.com.

My sister was clear about one thing she wanted to do in Colorado over a long Thanksgiving weekend: tour the New Belgium Brewery.

It was a bit of a head-scratcher for me. We have several great craft breweries in Denver, I told her, and we certainly could tour Coors in Golden. But she was adamant, so we drove north Wednesday to the home of Fat Tire.

She said that her co-workers at Northwestern Medical Center in Chicago wanted her to bring them souvenirs once they heard she was going. That jibed with an anecdote related by our tour guide, Ken Petroski. When New Belgium expanded its sales to Minnesota a few years ago, the premier liquor store in Minneapolis - Surdyk's - took out a full-page ad in the city's alternative weekly touting Fat Tire for sale. The store had to open an hour early the next day to accommodate the lines, and sold 400 cases in the first hour.

That's some serious buzz, and it's mostly the reason the quirky brewery on the north side of Fort Collins is now the nine largest brewery of any kind in the United States, up from 12th last year. Although New Belgium brews seven other brands, Fat Tire easily comprises two-thirds of the company's sales, several employees told me. The smooth amber ale seems to be on tap in most Colorado bars, and New Belgium now sells in 16 other states.

A new bottling plant opened in June on the company's 55 acres, allowing 700 bottles per minute, up from 300 in the old plant. The 437,000 barrels of beer they brewed last year is still a drop in the keg compared with the Anheuser-Busch plant in nearby Wellington, which pumped out 8 million barrels. But New Belgium's position atop the state's 92 other craft brewers is one of the reasons Colorado is the nation's top beer-producing state. According to the Washington, D.C.-based Beer Institute, Colorado produced 23.4 million barrels of beer last year, pushing longtime leader California to No. 2. According to the BI study, Colorado's beer industry - including importers, suppliers, distributors and retailers - contributes $12.4 billion to Colorado's economy each year.

But New Belgium's success is important not just for the popular beer it makes. Its just as much an affirmation of the workplace culture fostered by founder Jeff Lebesch and the environmental stewardship exhibited in nearly every aspect of the brewery.

In the late 1980s, Lebesch jettisoned a career as an electrical engineer to pursue a dream of making beer. It was a dream fostered by a bike trip through Belgium and his encounters with some of the folks who make the 600 brands of beer that originate in the tiny European nation. And his successful pursuit of that dream has yielded a "follow-your-fancy" philosophy Lebesch instills in his employees. Check out followyourfolly.com and you'll see what I mean. A strong, whimsical strain permeates the culture at New Belgium, and there's a prevailing sense that "we make beer here, not heart valves," as tour guide Petroski put it.

But underneath any deliberate silliness is a dead-serious commitment to sustainability. Alternative energy provides nearly 100 percent of the brewery's energy needs. Since a unanimous employee vote in 1999, New Belgium has purchased more than 6.6 million kilowatt hours of wind energy from a wind farm in Wyoming, providing 85 percent of the energy needed. Most of the other 15 percent comes from burning methane recaptured from the wastewater treatment facility built in 2002. The brewery also is working with a local energy startup to make biodiesel fuel from algae that grows partly from the carbon dioxide byproduct of fermentation.

It'll be interesting to see how Lebesch and his wife and co-founder Kim Jordan continue to balance the growing demand for New Belgium's beer with their environmental ideals and the freedom they allow their 300 employees. So far, they appear to be model employers and model corporate citizens. My guess is that they'll stay small enough to keep those goals within reach. I can only hope my sister's next visit exposes me to another company with as good a story.