Brewing seminar at Big Beers fest in Vail explores the world of ‘coolships’ |

Brewing seminar at Big Beers fest in Vail explores the world of ‘coolships’

It's likely you've only heard of coolships, or "koelschips" in the original Flemish, if you're a brewer or an uber beer geek.

"The style of fermentation is one of the oldest known ones in brewing history," said Jeffrey Stuffings, founder of Jester King Brewery in Austin, Texas. "It predates the knowledge of microorganisms: yeast and bacteria. It was a way to inoculate beer before brewers knew they needed to do that."

As the name implies, these large, open, shallow vessels were originally devised for cooling, taking the boiling liquid wort and spreading it out to create more surface area for the head to dissipate, Stuffings said.

"Cold night air was the cooling source," he said. "This predated things like refrigeration and heat exchangers. The microbes in the night air would fall into the wort and inoculate it and cause it to ferment very slowly. The Belgian brewing tradition is where this developed, and there's a small handful of American breweries at his point that are using coolships and using spontaneous fermentation."

“What our interest is with coolships and spontaneous fermentation is to make a beer very specific to a place and time. ... It’ll really only exist one time and can’t be recreated, based on the nature of the fermentation.”Jeffrey StuffingsFounder, Jester King Brewery

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Brewers from four of those brew houses — Stuffings; Jason Perkins, brewmaster at Allagash Brewing in Portland, Maine; Jason Yester, founder of Trinity Brewing Co. in Colorado Springs; and Chase Healey, co-founder of Prairie Artisan Ales in Tulsa, Oklahoma — will be part of an Experimental Brewing Seminar on coolships Saturday, Jan. 9, from 9:30 to 11:30 a.m., as part of the Big Beers & Barleywines Festival.

In this panel discussion, each brewer will spend about 20 minutes pouring two or three samples of beer, describing how it was made and discussing the role of coolships at his brewery, followed by a question-and-answer period.

Inspired by Lambic

Allagash was one of the first breweries in the country to embrace the idea of coolships. The brewery has made only Belgian-style beers since its inception in 1995 and began its spontaneous inoculation project back in 2007.

"We have always really admired the Lambic style beers, made in Belgium and, more specifically, in greater Brussels in Belgium," Perkins said. "Those beer are made using spontaneous fermentation, which basically means no yeast is added in the way most beers are made — cultured in a yeast storage tank and added to the beer."

Just as Champagne is a product of a specific appellation, so is the name Lambic revered in the beer world, and out of respect for the Belgian brewers who created it, Perkins does not call his beer Lambic, though it's modeled on the same process.

"We're putting wort into the coolship, and it sits there for a night," he said. "It's not really open fermentation, but open inoculation or open cooling. The wort comes out of the brewhouse at full boiling temperature and it's cooled over night, inoculated with resident yeast and microbes from our air."

The next morning, the beer is mixed in a fermenting tank to evenly distribute the microbes that have settled on top, and then it goes straight into used French oak wine barrels for one to three years. Allagash's coolship base beer is a blend of vintages, with about 25 percent aged for one year, 25 percent for two years and 50 percent that's three years old, giving the beer a multi-layered complexity.

Keeping it cool

When using a coolship, the air temperature has to be, well, cool, to knock out some of the thermobacteria that can make the beer not so pleasant, Stuffings said. Because of that, Jester King is limited to only making coolship beer in January and February. The goal is to make something that's tasty and drinkable but also truly unique.

"What our interest is with coolships and spontaneous fermentation is to make a beer very specific to a place and time, using the cold night air and the microbes that are in the air on a particular night," he said. "It'll really only exist one time and can't be recreated, based on the nature of the fermentation."

Perkins said he's excited that coolships have gained enough interest to garner a presentation at a festival such as Big Beers.

"I think there's still a fair bit of misunderstanding about the process and why folks use them," he said of the coolships. "Myself and others on the panel will be able to shed some new light on it, which should be pretty exiting."

If you go …

What: Experimental Brewing Seminar: “Koelschips,” part of the Big Beers, Belgians & Barleywines Festival.

When: 9:30-11:30 a.m. Saturday, Jan. 9.

Where: Rocky Mountain Ballroom, Vail Cascade Resort & Spa, 1300 Westhaven Drive, Vail.

Cost: Entrance to all festival seminars is included with the purchase of a Commercial Tasting ticket ($70). Seminar seating is first-come, first-served; reserved seating for this particular seminar is sold out.

More information: Purchase Commercial Tasting tickets, view the full schedule and learn more about the Big Beers festival at