At Good Word in Duluth, Georgia, owner-brewer Todd DiMatteo is using hand-carried buckets to move boiling-hot mash between the vessels of his brewhouse.
“You can do decoction, too, and it’s every bit as shitty as you think it will be,” he says.
I’d seen photos of DiMatteo’s decoction brew day, with rows and rows of orange buckets filled with steaming-hot wort, and I had to find out why he’d subject himself to an infamously labor-intensive process with such an improvised approach.
“It’s pretty arduous,” he says, “but it’s worth it.”
The Dualism of Decoction
There are two kinds of brewers in this world: those who think decoction is old tech made obsolete by modern equipment and well-modified malt, and those who hold this onerous process as a key to unlocking a nearly indescribable quality in the finished beer.
In one camp are the pragmatic brewers, including renowned brewing scientist Charlie Bamforth. “I don’t understand why anybody in their right mind would want to be doing decoction mashing,” he once said on the podcast of the Master Brewers Association of the Americas. “You don’t need it.” It’s more complicated, consumes more energy, requires more equipment, and is unnecessary with today’s highly modified commodity malt. (Bamforth does offer one argument in favor of decoction—we’ll get to that.)
On the other side of the schism are the brewers who skeptics might view as romantic or quixotic.
Sacred Profane in Biddeford, Maine, is a lager brewery that imports a variety of floor-malted Czech barley, which is famously less modified and therefore better suited for decoction mashing.
Cofounder Michael Fava says he wants their beers to have the character of the Czech lagers they love, even if it means doing things the hard way. He and cofounder Brienne Allen designed their brewhouse for decoction because it’s the best way to honor the unique Haná barley malt they use. If you’re brewing Czech-style lagers but not practicing decoction, Fava says, “you’re lying to the consumer and yourself.”
Old European brewing texts are full of elaborate mash programs meant to get the most of whatever grains the brewers had available. The Austrian, Bavarian, and Bohemian brewers who refined decoction were working with higher-protein barley strains, and the results rewarded the process; single-infusion mashes wouldn’t have made the same beer. The golden lagers they developed managed to dominate world beer culture anyway.
Today’s barley varieties and malting practices have modernized and moved on, transformed by industrial lager brewing and supported by a vast supply chain. Technically, it’s true that decoction is unnecessary.
Yet as craft lager continues to blossom, and as new or forgotten barley strains find space in farmers’ fields and on maltsters’ floors, decoction is making a small-scale comeback. What was once a traditional workaround to smooth out the inconsistencies of raw materials is now something else—it’s a technique to differentiate lagers and showcase the distinctive malts available today.
Decoction Details
Decoction changes the flavor of the wort, but it also changes the ratios of fermentable and unfermentable sugars, and it affects the protein levels, oxygenation, and color of the wort.
The result is complex, and talking about it often stretches the brewer’s vocabulary. They may call it “deeper,” “richer,” “maltier,” or “fresh-baked.” But those don’t paint the whole picture.
Nearly as difficult as identifying those if-you-know-you-know qualities is actually doing a decoction. The 18th-century Bavarian brewers who developed the method were working with inconsistent raw materials, no understanding of enzymes or the mash’s molecular minutia, and no simple thermometers, not to mention restrictive brewing laws and thirsty, increasingly choosy consumers. Decoction was a necessity.
German brewers perfected the process of boiling a portion of the mash and adding it back to raise the mash temperature into the zones preferred by enzymes—and they didn’t know the enzymes, but they knew fermentability. Besides hitting those temperature steps, boiling the milled malt also helped to break down the grain’s cell walls, doing the modification work that malthouses had yet to perfect. A brewer might perform those steps—divide, boil, recombine—once or as many as three times to guide the mash through the various rests that modern brewers can hit with steam-jacketed mash mixers.
Obviously, though, ramping up the temperature and hitting the rest targets isn’t the same as boiling some of the mash. Decoction’s adherents posit that the elemental action of the boil does more than further modify protein-laden malt—and that it even goes beyond the Maillard and caramelization reactions that create flavor compounds.
Decoction is fractal in its effect—the closer you look, the more variables it introduces to the system. It impacts foam quality, wort color, oxygen pickup during transfer, and oxygen elimination during boiling, not to mention body and fermentability—that’s all part of the decoction package.
Designed for Decoction
Sacred Profane’s cofounders designed its brewhouse for what Fava calls “technique-driven beers.” They’re coaxing the flavor and character of their lagers from simple ingredients through triple decoction, open fermentation, natural carbonation, and careful service in their Czech-inspired “Tankpub.”
To facilitate decoctions, the brewhouse has a cereal cooker—a small kettle that’s about one-third the size of the boil kettle—plus two-inch piping between the mash vessels and the cereal cooker, and a flexible impeller pump that moves mash around the brewhouse.
It’s the system’s small details that make big differences in the process. Flexible impeller pumps are gentler on the mash, minimizing problems such as slow runoff down the line. The cereal cooker is sized to bring the decoctions up to boil rapidly. “It can take lots of time to bring mash up to temp in a big vessel,” Fava says. “We’re never waiting around for grain to boil.”
One of the biggest challenges of decoction is the time commitment. A triple decoction, even if you boiled for only 10 minutes at each stage, can add several hours to a brew day—it takes time to transfer the mash and bring it to a boil. Streamlined wort-flow and pumps sized to move thick mash around help with the pace. Adding a third vessel to the typical two-vessel craft brewhouse setup also is ideal, making the process more straightforward while speeding up brew days.
Owner-brewer Ian VanGundy spent two months carefully customizing the design of his three-vessel, seven-barrel brewhouse at Blackbird in Wake Forest, North Carolina. His goal was a system that facilitates painless decoctions—literally, in his case, because he’s gone through multiple knee surgeries in recent years and wanted to minimize how often he has to climb the steps to the brew deck. VanGundy was committed to brewing approachable yet interesting styles because customers are thirsty for those in the hot, humid Carolina climate. Decoction provides interest and depth to styles designed for drinkability.
Instead of a whirlpool, he opted for a steam-jacketed mash cooker along with an up-sized lauter tun and brew kettle. Three-inch piping connects the vessels, and a five-horsepower pump moves mash and wort around the brewhouse.
“Forget the whirlpool,” VanGundy says. “Put in a second kettle with impellers. The whirlpool is a dumb piece of stainless steel. A mash cooker adds to your process.” The cooker also facilitates cereal mashing, making it easier to incorporate large portions of corn, rice, and other cereal adjuncts. “Now we can make fun, cool lagers all the time.” While it’s easier to do decoctions in a brewhouse that’s designed for it, retrofitting an existing system isn’t terribly difficult, says Ralph Eibert, VP of brewing operations at Prospero Equipment.
“A good welder and a few penetrations” are all it takes to add the wort pathways between vessels, he says, and many “off-the-shelf” brew systems have considerations for the necessary process piping.
Ad Hoc Adaptations
Khris Johnson, co-owner and brewmaster at Green Bench in St. Petersburg, Florida, made their two-vessel brewhouse decoction-capable by adding a mash cooker to the brew deck.
He says there was temptation to add a whirlpool or other upgrade to make the brewery more efficient, but the chance to gain greater control over the wort and fully explore the esoteric German technique was too enticing. Today, decoction is part of Green Bench’s brand identity, and Johnson is one of the brewers whom others call when they have questions about the process.
For Johnson, going from single-infusion to the flexibility afforded by the cooker was exciting and empowering. The new variables he can control mean that he can more closely realize the brews he imagines.
“I have a beer in mind,” he says, “and I use decoction to build the fermentability profile and regulate how much decoction character I want to have.”
Green Bench Pale Lager Beer—a Munich-style helles—gets a single short decoction to retain its pale color while adding dextrins to the wort, building a body that buffers the hops but doesn’t taste sweet. For the Dunkel Lager, they twice decoct for 20 to 30 minutes to deepen the beer’s color and underscore its malt character.
Czech brewers typically do two decoctions for their pale lagers, even if the famous Pilsner Urquell gets three. Green Bench’s Czech-style pils, Pohlednice, also gets a triple decoction with the same Haná malt used at Sacred Profane.
“I try every type of pils malt I can get,” Johnson says about his approach to recipe design. With the range of malts available from smaller malthouses now—including batches made from local barleys or made to resemble old-fashioned varieties—decoction can be an important tool. It can help to extract the most potential from those malts—in flavor and character as well as efficiency.
Green Bench could have leaned into throughput and production capacity, but decoction unlocked Johnson’s creativity, opening new paths to brewing what he most wants to drink. “Without decoction, I have fewer tools to make what I’m trying to make,” he says.
Adding a small cereal cooker to an existing brewhouse isn’t the most expensive upgrade, but it can still run into five figures—especially once additional plumbing and pump infrastructure are considered. But there’s another option for the decoction-curious brewer on a budget: spending time instead of money.
That’s the approach taken by Whit Lanning at Burning Blush in Mills River, North Carolina, south of Asheville. The brewery opened in 2019 with a two-vessel system of the typical kettle-whirlpool and mash-lauter tun. Lanning says he developed his decoction process to meet the local demand for characterful lagers.
“Asheville is a beer town, and even nonbeer geeks are familiar with decocted beer,” Lanning says. “Decoction moves the needle. It’s worth the time.”
His direct-fired system requires a little more care when running a decoction, but the setup is simple. Just above the mash tun’s false bottom, Lanning added a valve to the sight glass where he can add mash that’s cooked in the kettle. He moves about a third of the grist into the kettle, using more water than usual—about three quarts of liquor per pound of grist. The process adds four to six hours to the usual brew days, but for Lanning, it’s worth it to have more control over fermentability and the ability to fine-tune a beer’s balance and flavor.
For DiMatteo at Good Word, his bucket-brigade decoction method adds only a couple hours to the usual brew day—but he does have to carry all those buckets of hot wort up the brew-deck steps. (He’s since ditched the Home Depot buckets for food-grade virgin HPDE ones.) DiMatteo’s 10-barrel, three-vessel brewhouse anchors a bustling brewpub, but space and cost considerations led him to develop a decoction process that used more elbow grease than capital. “It’s not awesome,” he says about the labor-intensive approach, “but we sell more burgers than lagers, and this works pretty well.”
He makes the point that there is always something to spend money on, and he’s less interested in brewhouse efficiency and throughput than he is in excellence. He says he’s not afraid to take the hard road if it’s the one that leads to his imagined destination. (“I’m in it for the glory,” he quips.)
He says he lets style, tradition, and—most of all—his palate decide what decoction regimen to apply, from single decoctions with quick boils for the Kölsch to lengthy triple decoctions with 25-minute boils for darker lagers.
The New Wave of Decocted Craft Lager
Decoction is intrinsic to the character of these lagers, deepening not only their malt flavor but also the stories that their brewers can tell. It’s a point of differentiation that launches conversations between the drinkers and the breweries practicing the technically “unnecessary” technique.
That brings us back to Bamforth’s one concession to the process. He says that modern “high-quality” malts make decoction inefficient and superfluous—but what about malts that aren’t made with maximum extract in mind?
Small-batch malts are growing in availability and in popularity, and even some larger maltsters produce relatively less-modified malts to meet brewer demand. Bamforth says that the only argument to make for decoction is that it may be able to deliver a particular flavor quality desired by the brewer.
None of these decoction brewers say they do it because that’s what tradition dictates. Instead, they say it’s to improve the quality of flavor, body, and foam.
From Moravian Haná barley to American six-row and new cultivars being trialed by farmers, brewers have the opportunity to pull more flavor from base malts than ever before. And decoction can emphasize the flavor impact of idiosyncratic malt varieties in a way that’s repeatable.
Other benefits include flexibility and the ability to contend with malt that may fall short of the highest quality. Barley crops and the regions in which they grow are changing alongside the climate, and decoction may be a key to excellence in situations where single infusion may fall short.
