It’s romantic, especially in autumn, to daydream about rustic, woods-dwelling breweries stoking fires in a forest clearing. Atop the conflagration sits a gleaming—well, for this reverie, let’s make it charmingly worn—copper kettle, boiling away like a witch’s cauldron. Flames heat the wort within, the snap of the wood punctuating the audible boiling noise. Perhaps, like Bob Ross and his happy trees, we can add the melody of a nuthatch or warbler song in the distance.
All very nice, quite picturesque. But the two American breweries who wood-fire these copper brewing kettles aren’t doing so for the provincial tableau; for them, it’s much more practical.
“We’re saving in efficiency, cost and time. Those are three huge factors in manufacturing,” says Van Carney of Pen Druid Brewing in Sperryville, Virginia, who uses a single-walled, custom-made copper kettle to boil wort that becomes the brewery’s beer. “And it’s cool because you get to build fires.”
Likewise at Scratch Brewing Company in Ava, Illinois, where Aaron Kleidon and his brewing team use a 300-gallon copper apple butter kettle to boil their wort over an insulated fire box.
“It’s kind of a combination of old technology with the fire and new technology with insulation around that fire box. The ceramic fiber wrapping pulls the heat in so every BTU from the wood we burn goes straight into the liquid in the beer,” Kleidon says. “It’s really efficient.”
A brew kettle serves two purposes: It boils wort, which kills unwanted bugs in the liquid and extracts hop bitterness. It can also, when direct-fired, caramelize the sugars present in wort to create deep, rich malt flavors.
It’s the allure of caramelization (and the limited technology of the time) that led European brewers to direct-fire their kettles. Some still do today, including Zoigl breweries in Neuhaus and Windischeschenbach in Germany; and the vaunted Dupont in Belgium. But American brewers who do it with wood are few—perhaps as few as two.
“I couldn’t really find an example of what we wanted to do exactly, so a lot of the [plans for building our wood-fired kettle] lived in my head from building a lot of wood-fired ovens and smokers,” Scratch’s Kleidon says.
Buying wood also has the benefit of being relatively cheap compared to buying propane or natural gas. Scratch estimates its brewers use a wheelbarrow and a half of wood to boil the kettle for two hours.
But what the fires offer in efficiency and cost, they lack in control. Modern kettles boast dials and displays to help brewers control the temperature of the wort; playing with fire is sometimes … like playing with fire.
“It takes a little bit of learning, like when to throw a log on and when not to. You can have pretty epic boil overs if you’re not conscious of that,” Kleidon says.
He has the method down pat now, and Pen Druid does as well.
“People were like ‘Really? You don’t want to do that. Where’s the control, bro?’” Carney says. “It was a mental thing for them, like, ‘This is how you do things.’ And I was like ‘No, this is what we want to do.’”
Though their decisions are practical, Pen Druid and Scratch admit there’s a bit of sentiment attached to the wood-fired method as well.
Both breweries use copper kettles made by hand by Caldwell Mountain Copper in Fincastle, Virginia, a family-owned company with just a few employees. Kleidon had the idea to use an apple butter kettle as a brew kettle because he’d seen them around his grandparents’ and great-grandparents’ homes. The first one that Scratch used was borrowed from Kleidon’s neighbor, an auctioneer, and dated to the 1860s.
The simple copper vessel manages to combine time-honored traditions with modern efficiency, and not least of all, a bit of that wooded romanticism.
“Obviously we’re looking for that caramelization, but also there’s kind of a sense of self-reliance here. Wood’s here, we can cut it and burn it to generate all the heat we need to make our beer. There’s always brush that needs to be cleared or limbs that fall during a storm,” Kleidon says. “It’s here, and that’s why we use it.”