New Belgium Brewing Co.'s brewery is one of the most modern facilities in the country, with a shiny five-vessel brewing system that is gloriously efficient. Yet deep inside the same building, brewer Peter Bouckaert can roll up a large warehouse door, revealing row on top of row of wooden wine casks. There's nothing efficient about the beer fermenting inside these.

New Belgium may have reached the 21st century before most others, but it didn't leave behind the soul of beer. Here in Fort Collins, Colo., there are bicycles, small trees and large classic Belgian beer signs just a few feet from a computer screen that monitors the state-of-the-art brewery.

This is a brewery that began with a five-hectoliter brewhouse (and a capacity of eight-and-one-half barrels a week) in 1991 and last year sold 145,246 barrels in 10 states. It is bursting at the seams, with office space being added on one side of the complex built in 1995 and eight new 2,100-hectoliter conditioning tanks going up on the back part of the building.

One day late in June, the giant white tanks - which come on line in August - loomed above four large (60-hectoliter) wooden wine barrels that had just been delivered. They are Bouckaert's newest toys, in which he will continue his experiments with a wood-aged sour beer that didn't even get a name, La Folie, until recently.

"I think it's a good illustration of what New Belgium is," said Bouckaert, who came to New Belgium four years ago after working 10 years at the Rodenbach Brewery in his native Belgium. "Luckily we have Fat Tire, and that lets us do all these other things."

Most of New Belgium's sales are Fat Tire - which has turned into a cult beer that those east of the Mississippi demand friends bring them when they venture west - but the brewery produces a wide range of Belgian-inspired beers, ranging from its Sunshine Wheat to an aggressive Trippel.

Perhaps La Folie will be added to that lineup, but Bouckaert can't say when or how. Right now bottles are sold only at the brewery, at $5 for a 375 ml bottle. The first batch was bottled in March, three years after experiments began.

"We figured 12 barrels, OK, buy 12 barrels, then why not buy 12 more?" Bouckaert said. Eventually he was working with 80 smaller French wine barrels and always experimenting. He used wort from regular beers plus special brews designed to provide different nutrient levels. He experimented with different ways of cleaning the kegs, sometimes washing them with beer, other times scraping them.

"I'm not after the wood flavor here," he said. The wood provides a breeding ground for micro-organisms that influence the beer's flavor. He has purchased a variety of brettanomyces and other wild yeasts, then found others along the way - harvesting what returns in old kegs of New Belgium beer, for instance.

"It's incredible the amount of testing I get done on anything," Bouckaert said. Of course, New Belgium has a state-of-the-art laboratory, and eight employees work in quality assurance.

Bouckaert tasted the beer every 14 days, and the tastings became among the best attended at the brewery. In March he blended 20 casks and the bottling turned into a party.

"We had a hot tub in the back, ribs," said marketing director Greg Owsley. "About 30 people, including spouses, were in and our during the day. A lot of the older New Belgium employees were reminiscing about the old days."

Bottles were hand corked and hand labeled. Then Bouckaert numbered each bottle. Inside is a classic Belgian sour beer, sometimes intense and quite complex. The next batch bottled will probably be a little different. "As a brewer, I'm never going to be happy," Bouckaert said. "We're still working on Fat Tire."

He smiled broadly. Backed by New Belgium's lab, his own experience and apparently unquenchable curiosity, he's often both engineer and scientist. Yet ... "it's not strict science. There are judgment calls -- Why do this?" he said, asking himself the question, then answering, "I don't know - I think that's the best way, that's why."

He plans to visit Belgium in September to talk with other brewers about using wood in fermenting beer.

Meanwhile, the beer will be available only at the brewery.

"There are no real plans around it," Bouckaert said, responding to a question he is asked often these days. "There were no plans when we started ... 'What are you going to do?' people ask me." He paused as a smile started over his lips. "We are going to do something."

July 2002