Wander Brewing’s new coolship (an anglicized term from the Dutch/Flemish word, koelschip) may not be the sexiest-looking piece of equipment in the brewery, but it’s arguably the most romantic. This large, shallow and open stainless steel vessel will be used to make spontaneously fermented ales, similar to how they’re made by Lambic breweries in Belgium and, as of recent years, a handful of breweries in America.
Wander’s coolship was designed to hold a full, 20- to 25-barrel batch of beer. After the kettle boil, the hot wort will be pumped into the open tank, where it will be allowed to cool down overnight. Essentially, a coolship is an inefficient heat exchanger that is used to slowly chill wort while capturing airborne yeast and bacteria. Exposed to the open air, the wort will become inoculated by wild yeasts (including various strains of Saccharomyces and Brettanomyces) and bacteria (including various strains of Lactobacillus and Pediococcus), and then it will be pumped into barrels where it will begin to slowly ferment.
Some Washington breweries have dabbled in spontaneous ales using ramped-up cultures, small makeshift coolships and barrels, but Wander’s coolship just might be the first of its kind to be used in Washington.
“There are many ways to do wild ales, but I want to do it the traditional way — with a coolship,” Wander co-owner Chad Kuehl says. “There’s just something fun and exciting about it. Plus, we’re in such an amazing environment and a great agricultural area, so why not try it here?”
Chad and his wife Colleen hope to do their first spontaneously fermented batch of beer this fall, when the airborne microbes are more favorable. Each batch will require at least 10 months to ferment and condition, so the first coolship release wouldn’t be until sometime next summer.
Style-wise, the Kuehls plan to make “Lambic-esque” beers using aged hops, and they say their recipes will evolve.
Much of the wild yeast and bacteria will come from the air, but over time the wild cultures will begin to spread and thrive within the porous staves of the barrels, which will only add to the resilience and terroir of future batches.
Fermenting beer with a coolship is a risky endeavor because the beers don’t always turn out as planned. Pitching pure cultures of wild yeast and bacteria is much easier and more controlled. But many argue that you don’t get the same depth of flavors, plus you wouldn’t get the locally derived influences.
The Kuehls feel the risk is worth it. “Sometimes beers don’t turn out and you learn,” they say. “Other times they turn out really well, like our Wild Warehouse Farmhouse Ale, which was our biggest success and the first barrel-aged beer we ever did.
“This new coolship keeps Wander evolving as a brewery. We like doing innovative stuff, and we need to continue to challenge ourselves.”