GRAND RAPIDS, MI — If you like beer and the Detroit Tigers, a couple of home brewers are busy finishing your new church on West Leonard Street.

Chris Andrus and Max Trierweiler, friends since first grade, are putting the final touches this week on the Mitten Brewing Co., the city's newest brewpub, opening Oct. 25 in a historic, 121-year-old West Side Grand Rapids fire engine house.

Since last year, the two friends have been busy renovating the old structure, board by board, turning the decommissioned firehouse into a vintage baseball-themed 3-barrel system nanobrewery and pizzeria located at 527 Leonard Street NW.

It’s been a ton of work, but “it feels like home for sure,” said Andrus, a professional musician and sound engineer. “It’s better than we imagined it would be.”

Four seats from old Tiger Stadium sit inside the entrance to the brewery, which is shaping up to be a shrine of sorts to the Detroit Tigers. A large Olde English D sits aside a bat behind the bar, which is made from reconditioned wood yanked off the interior walls during the renovations. The tables are made from the same kind of ash wood used to make baseball bats.

On the bar are transfers of old baseball imagery and newspaper stories. On each of the partners’ heads, a Tigers ball cap.

"We want this place to be known as the place in town to go watch the Tigers," said Andrus. That means no changing the channel on one of the five TVs if Detroit is playing. "Rod and Mario will be blaring in here."

The partners are busy this week brewing initial beer batches on their new, all electric system. Trierweiler and Andrus are homebrewers themselves, but they turned the kettle reins over this month to new brew master Wob Wanhatalo, who joined the new operation after several years brewing at The Hideout.

“We’re going to give him some free rein,” said Trierweiler.

The Oct. 25 opening will be just in time to catch the Tigers in Game 2 of the World Series (fingers crossed). The brewery will eventually have eight beers on tap, although they are initially opening with just three beers, a peanut butter and chocolate Cracker Jack porter, a traditional German hefeweizen, and a pale ale.

Trierweiler comes to the beer business after working in marketing for the Trivalent Group tech firm of Grandville, and Andrus from the music business. The two got into home brewing about five years ago “with the dim notion of wanting to do this someday.”

Sometime in 2009, they started designing a business plan and lining up investors. After going to their friends and family, Trierweiler said they soon discovered that many local investors are actually quite eager to get in on the craft beer boom underway in Michigan for the last few years.

"Numbers don't lie," he said. "Year after year, growth in the craft beer industry is jumping double-digits, percentage-wise."

“There’s so much room for growth. One of the questions I keep getting asked is where are there going to be too many breweries,” he said. “I don’t see it happening for at least another five to 10 years.”

Even with investors lining up, the two brewery partners decided to do much of the interior engine house remodeling themselves; a kind of self-imposed crash course in adaptive reuse, heating and cooling, plumbing, electrical wiring, and wood-working techniques learned, in part, by watching YouTube videos.

“We challenged ourselves to do this,” said Andrus. “It’s a pride of ownership.”

They are eager to open as the only Grand Rapids brewery on the city’s West Side. An undeserved bad reputation has plagued the West Leonard Street corridor in recent years, they say. The two point to the success of Brann’s steakhouse and the rebuilt Arnie’s restaurant down the road as testament to the vitality of the surrounding business district.

The engine house was the first building they looked at when they began searching for a location. The historic structure was decommissioned in the 1960s and housed a couple apartments and a dance studio before Andrus and Trierweiler bought it.

“Nothing else had the charm and character that this building had,” said Andrus. “And no neighborhood besides the West Side made any sense to us.”

Gourmet pizza will be available for dine-in or carry out, and six-packs of beer also will be sold to-go. The limited menu is a way to "focus on one thing and do it well."

The decision to make the brewpub sports-themed was rooted in a long love of the Tigers, and the belief that the game has strong cross-demographic appeal. It’s also a way to stand out among the ever-widening craft beer industry in Grand Rapids.

The brewpub will open at 6 p.m. next Thursday. Andrus and Trierweiler said the establishment’s initial hours will be variable for the first few weeks, but they eventually plan to be open 11 a.m. to midnight Monday through Wednesday, and until 2 a.m. Thursday though Saturday. The pub opens at noon on Sunday.

Email Garret Ellison or follow him on Twitter.