Robert Allen

Detroit Free Press

GRAND RAPIDS – It lives in underground caves for at least a year, absorbing the essence of used bourbon barrels before it's released to the public.

It's helped make Michigan a world-class force for quality craft beer, and it's one of the most coveted beverages during its annual release at winter's end.

"If there was a dollar for every time someone asked about KBS throughout the year, I don't even know if we'd need to be open for an entire month," said Scotty Kearns, manager of 8 Degrees Plato beer store in Detroit. "There's that much draw to it."

Bourbon barrels rise in demand for beer-making

With two kinds of Belgian chocolate, two types of locally-roasted coffee, lots of oats, roasted grains and barley, and about 11.2% alcohol by volume, Kentucky Breakfast Stout (KBS) is a heavy-hitting signature concoction from Founders Brewing, one of the beer makers that's helped Michigan (and Grand Rapids specifically) a top-flight reputation among beer connoisseurs.

Detroit Untapped: The Craft Brewery and Distillery Tour - The Detroit Bus Company

Like with Bell's Brewery's Oberon wheat ale, the annual release of KBS is something of a celebration. Unlike Oberon, Founders' KBS is quite limited and disappears quickly. People have been known to camp out in the cold for it, and 8 Degrees Plato uses a raffle-ticket system for customers eager to buy the bottles.

KBS releases in Michigan on Monday, and everywhere else April 1. The bottles and kegs are spread across Founders distribution footprint that includes states on both the Pacific and Atlantic coasts.

National poll taps Grand Rapids as America's best beer scene

Founders brewmaster Jeremy Kosmicki said KBS started as an experiment with a few bourbon barrels in the early 2000s, but people didn't know they wanted it.

"Those 4-packs sat in there, and nobody cared," Kosmicki said.

As the craft beer boom developed and websites tracked ratings, a wave of discerning drinkers awarded high marks to KBS: It's now ranked 16th in the world on RateBeer and 19th on Beer Advocate.

"Beers like KBS started to generate some buzz, and that really kind of set that off as far as the hype train," Kosmicki said. "At that point, it became like people were actively pursuing trying to get this beer. And we're never able to make enough."

Barrel-aged beer has grown increasingly popular in recent years, adding a level of complexity to brews that can't be matched in stainless-steel tanks. KBS was one of the first to gain widespread appreciation, and distribution has spread across the country, recently adding California. Barrel-aged brews had a strong presence at the 2016 Michigan Brewers Guild Winter Beer Festival in Grand Rapids last month.

Aged in caves

We recently took a trip with its makers about 3 miles from the brewery to Michigan Natural Storage to get a taste of the KBS aging process. To reach the caves, you take an elevator ride 85 feet below Grand Rapids. The former gypsum mines spread for about 6 miles of mostly narrow passages where the temperature and humidity are tightly controlled.

"This is an old sea bed, this used to be an ocean a bazillion years ago," said Jason Heystek, Founders vice president of planning, packaging and inventory. "But you can see the sedimentation, the different layers of rock. So the gypsum's the really soft stuff."

It's hard not to grin at the deep, woody bourbon-chocolate aroma of thousands of 53-gallon oak barrels lining the gray, rocky cave walls. Many of the barrels previously aged Jim Beam, Heaven Hill, Buffalo Trace or Maker's Mark.

"My hard and fast rule is: If I don't like the whisky, I don't want the barrel," Heystek said.

He said Founders is not the only one using the caves, and other clients range from beer companies to government entities. The location dates to the 1890s, when the Alabastine Mining Company started mining gypsum. Operations continued until 1943, when the company went bankrupt, according to the storage company's website. The storage site was started in 1957.

Among the 7,000 barrels on racks are future KBS and Backwoods Bastard, a Scotch ale. Heystek sprayed sanitizer on four of the barrels and popped out the bungs, removing samples with a turkey baster to give us tastes comparing Backwoods and KBS brews aging since as far back as 2011. The alcohol bite was more noticeable in the fresher samples, while the older ones had more velvety, dessert-wine flavors.

“The longer everything sits, the more oxidation you get," Heystek said, motioning to a several-years-old barrel. "So this really has a lot of sherry — like, port things, going on with it. It's interesting.”

He said the barrels that held whisky longer tend to have deeper flavors, but that some blending is necessary to hit the flavor notes they're going for.

"We want the bourbon character to not be completely outrageous and the wood to still be there," he said. "You get all the vanilla and tannic stuff out of the barrels, too."

A consistent temperature is essential to aging beer, and the caves where the beer is stored are held at about 38-40 degrees Fahrenheit. The caves are naturally cool, but the KBS barrels are kept in sealed air-conditioned areas to maintain temperature and humidity. Kosmicki said that other than those two crucial factors, the caves themselves don't have much effect on the beer-aging process.

The barrels are removed via freight elevator, 16 at a time, and each weighs about 550 pounds when full with 53 gallons of liquid.The beer is trucked from Michigan Natural Storage, where it is pumped from the barrels into tanks, run through centrifuges, settled in bright tanks and carbonated before it's packaged.

Kosmicki and Heystek personally taste samples from about 90% of the barrels, ensuring the right flavors are there and watching for signs of infection.

The brewery announced in January that it's expanding — not only to fill the city block of its current operations, but also to an additional, barrel-aged-beer focused location in Grand Rapids. It's expected to bring the brewery from 400,000 to about 1 million barrels produced in a year.

Short's Brewing sells across state lines for survival

In 2014, Founders was the 17th-largest craft brewery in the U.S. It's the largest in "Beer City" Grand Rapids, and it leads the state in output next to Kalamazoo-based Bell's Brewery.

Lately, beer enthusiasts have watched other large craft breweries sell out to macro-brew companies such as Anheuser-Busch InBev and Constellation Brands (Corona Light, Pacifico, Svedka, etc.). Founders in December 2014 announced it was selling 30% ownership to Mahou San Miguel, a Spanish brewery.

"I'm ecstatic we went that route," Kosmicki said. "They have no interest in telling us what we do."

He said it's also it's opening opportunities in international markets. Meanwhile, craft-beer drinkers across Michigan and the U.S. in the next few weeks will be watching for that brown and tan-colored KBS label. Some locations, such as HopCat Detroit, throw release parties.

"There's something to the mystique of something special to find out in the stores, but it's a lot to live up to," Kosmicki said. "Any time you get that much hype for something, it's like, 'Well, I hope people like it. I hope this isn't a disappointing year or something.' "

Kearns said it's one of the top five if not the most desired annual release.

"The beer itself is unlike any other barrel-aged beers out there: The roundness of it. Drinkability, and just the allure of getting something that is hard to find," he said. "People always want what they can't have. It's one of those you gotta have once — and once you get it, again and again."

Spirits of Detroit columnist Robert Allen covers alcohol for the Free Press. He can be reached at rallen@freepress.com or Untappd, raDetroit; Twitter, @rallenMI; Facebook, robertallen.news, and Periscope, @rallenMI.

Founders Brewing Co. KBS 2016 launch party at HopCat Detroit

Featured drinks are to include 2016 Kentucky Breakfast Stout as well as Founders' Project Pam, a black IPA aged in maple syrup bourbon barrels, and Mango Magnifico, a mango ale with habaneros

Time: 5 p.m. Monday

4265 Woodward Avenue, Detroit