GRAND RAPIDS — A line was forming outside on the morning of HopCat’s sixth anniversary, but owner Mark Sellers was concerned first of all with the crowd inside.

“When we opened,” he told the congregation of about 25 employees, “I didn’t even know if we’d make it to one year. Now we’ve made it six years, and we’re setting records every year, and that’s thanks to all of you.

“Now get to work!” he added wryly, and opened the doors for the anniversary celebration. The all-day event featured limited release stouts, free “crack fries,” and a crack fry eating contest so intense that an impromptu halftime was needed to help the kitchen keep up.

It was clearly a successful day for one of the most celebrated beer bars in the country. But while success has become the standard outcome for everything HopCat does, it wasn’t exactly what Sellers planned for at the beginning.

Sellers just wanted the place to stay afloat at first. He didn’t anticipate the craft beer craze. He wasn’t thinking that far ahead. “I told my manager,” he recalled, “that my goal [for the first year] was to break even so I could have a bar to hang out in.”

The vision was a place for “the true beer geeks,” a place that emphasized craft and kept out corporatized macrobrews. People told Sellers it would never work. “I got lucky, I guess,” he said.

Whatever caused it — luck, intuition or maybe just good taste — Sellers isn’t too concerned about his personal success with HopCat. He’s most gratified by the prosperity it has brought to others. Between HopCat and the other bars he owns (under the umbrella of Barfly Ventures), Sellers employs more than 430 people who have made over $7 million in wages since he opened HopCat in 2008. “It really gives me a sense of pride that I’ve given that many people a way to make a living,” he said.

Two of the staff making their living at HopCat are Ernest Richards and Bobby Edgcomb, the brewers behind the spectrum of stouts released for the anniversary. Both enjoy the challenge of brewing for a place where the in-house beers aren’t the only option or even the main attraction. Edgcomb said that, because their beers face more competition, the brewers “have to bring their best” in order to get any attention.

Their best on this occasion was the Oil Rigger, a rich but smooth Russian imperial stout, plus six flavor-infused variations on it: Chocolate raspberry, coffee marshmallow, crème brûlée, molé, orange brandy and vanilla bourbon.

The stout’s full body offered a nice backdrop to each of these flavors, the most popular of which seemed to be the molé, a beer that smells a little like French Toast but finishes with heat from ancho and chipotle chili peppers. Special edition bottles of the standard Oil Rigger were sold to a limited number of customers, but all the flavors (plus 2012 and 2013 brews of the Oil Rigger) were available on draft.

You can expect more crack fries, more brews, and more people to be on hand this time next year for the seventh anniversary. If you can’t wait that long for a HopCat party, though, you’re in luck. Sellers plans to announce the opening of a third HopCat restaurant soon. He wouldn’t say where, exactly, but he would say this: “If you keep going east past East Lansing, you eventually hit another city.”