Good Beer Hunting

Message in a Bottle

Saison D’etre — The Je Ne Sais Quoi of the Strain that Defines Convention

Tracing the evolution of a living thing is like unrolling an ancient map: to follow the biological cartography of nature’s inevitable bobs and weaves, one must be precise and careful, lest she get lost and follow a crease thinking it a tributary. So complex and winding is nucleic design that it’s incredible to think we’ve managed to understand and record it at all, never mind with such purpose and agency that modern scientists can play demigod at a genetic level.


It’s difficult enough to map the genome of fauna we know and can track the physical evolution of through fossil records and living offspring. Doing it with a single-celled eukaryote, especially one as varied and mutable as yeast, seems impossible on paper. There are hundreds of known strains, and countless unknown. Even through a single brewing lifecycle a strain can mutate and drift, meaning even a known yeast can (potentially) be genetically different in a matter of weeks. The speed of mutation and variance of natural strains makes the genes of yeast—and thus the possible flavors it produces in beer—a veritable Rubik’s cube of possibility.

(For the record, a Rubik’s cube has 88,580,102,706,155,225,088,000 possible permutations.)

The story of Saison—and its journey from seasonal brewing in Wallonia, Belgium, to year-round availability in taprooms all over the U.S.—is arguably not one of evolution but, rather, mutation. The style, at its core, thrives off the randomized power of genetics. It generally eludes consistent definition and tasting notes, as explained by Phil Markowski in his book, Farmhouse Ales, “expecting Belgian and French beers to follow [a] pattern can lead to disappointment and frustration.”

“While critiquing and deconstructing a beer can be lots of fun, a preoccupation with style definitions can lead to a reflexive habit (when not officially judging beer, that is) of evaluating and assessing whether a brew is worthy simply by whether it fits in a standard style definition,” he continues. “Perhaps no other family of beers can frustrate the style police like the farmhouse ales.”

And that’s because of the wonders of our favorite fermenter, Saccharomyces cerevisiae. The question, then: is there a style more driven by yeast than Saison?

Saison—and this writer would be remiss not to mention its step-brother, Biere de Garde—came into the world in the scientific and biological Wild West before Louis Pasteur, where standardization, clean equipment, and any sort of sanitization were non-existent. Every brewer had different recipes, and likely, even in the same region, different wild yeasts inoculating their brews. Pasteur didn’t describe and record yeast fermentation until 1857, putting him and his discovery closer to us in 2018 than those who likely brewed the first, spontaneously fermented proto-Saisons.


Every very early Saison, as a result, was likely wild. Spiked with lactobacillus. Doused with pediococcus. They were brewed in the winter to prevent the run-away ester and phenol creation that comes with warmer temperatures, but without any real hygiene in brewing systems (not to mention people), all those microbial homofermentive colonists brought a distinctive tartness to what most people consumed on a regular basis.

The modern Saison is a gustatory exploration: moderate-to-high ABV, dry, peppery, but also appropriately hoppy. Those without any Brettanomyces (which is most of them) aren’t funky, but rather ironically clean in the dirtiest way possible. Those in the vein of Saccharomyces cerevisiae var. diastaticus—sometimes considered a contaminant by White Labs—attenuate aggressively, and produce flavors to match.

Pasteur didn’t describe and record yeast fermentation until 1857, putting him and his discovery closer to us in 2018 than those who likely brewed the first, spontaneously fermented proto-Saisons.

While it was rather unscientific, the activity of these very early yeasts laid the groundwork for that Saison Dupont you love so much. And that Brasserie Fantôme Saison. The distinctive flavor character of Saison is locked away in its genes (notably STA1, which encodes the glucoamylase that allows for hyper-attenuation, and very dry fermentations). This is why, in part, it’s hard to describe what one likes about Saison. Is it peppery? Crisp? Tart? Earthy? Phenolic? All or none of the above? Often the valuation comes down to thinking about how the style fits the beer, rather than how, in almost all other cases of beer evaluation, how the beer fits the style.

What we know as Saison originated in Wallonia, a region in southern Belgium. It shares a border with France and Germany, and has, through World Wars, geopolitical machinations, and blanket globalization, traveled. The farmhouse ale brewed to sustain farmers with little access to water and in need of extra calories has migrated westward, manifesting its own destiny to reach the palates of thirsty Americans.


Food writer Michael Pollan has a theory that, in a lot of ways, maize—being that it’s easy to grow, nutritional, and multi-purpose—was not domesticated by us. But rather, more plainly, to supplant human exceptionalism for a moment, it domesticated us. We’ve spread what was originally a hard-kerneled cereal to nearly every corner of the globe, come to rely upon in for sustenance and fuel, to the point where corn is so ingrained in our culture that it literally makes up everything we eat:

“Corn is what feeds the steer that becomes the steak. Corn feeds the chicken and the pig, the turkey and the lamb, the catfish and the tilapia and, increasingly, even the salmon… The eggs are made of corn. The milk and cheese and yogurt, which once came from dairy cows that grazed on grass, now typically come from Holsteins that spend their working lives tethered to machines, eating corn.”

It’s not too much of a stretch to say the same about our beer and our yeast. While yeast naturally exists anywhere the wind can blow (you’re breathing it in, right now, as a matter of fact), certain strains, especially those with aspects humans see as beneficial like great tasting byproducts and gleeful intoxication, managed to find a way to ride human ingenuity into the brave new world. Yeast is ever-present and pervasive. Your gut flora is full of Candida albicans, which exists in the same genetic family as cerevisiae (Saccharomycetaceae, for anyone who cares), but has had significantly less time in the limelight compared to its cousin, mostly due to cerevisiae’s ability to ferment—and, in turn, benefit mankind.

As a result, humans have brought yeast with them everywhere they’ve gone. The pervasive myth/lore of human history says that our first farmers, and agricultural nascence, arose from the need—and/or desire—for booze. That the American colonists veered the Mayflower into Plymouth rock because they were down to their last six-pack. That Johnny Appleseed didn’t really care about food, but rather cider and applejack in a Midwestern wasteland of non-potable water. Our need to stay safely hydrated has driven many major anthropological milestones, catalyzed by the organisms that symbiotically benefited.

Saison yeast is no exception.

Thanks to some intrepid scientists mapping brewing yeast’s genetic code, we can trace domestication events of two major beer yeast strains around 1600 and 1650-1700 AD. These two “clean” strains include the common ale Saccharomyces cerevisiae and the workhorse Lager Saccharomyces carlsbergensis (now known as Saccharomyces pastorianus), both of which are still heavily used today, and present, generally, the same way every time they’re brewed. Variation in flavor for these yeasts is primarily derived from malt and hops, and they have remained, through proper propagation, relatively unchanged for centuries.

The Saison sub-variants, by contrast, have continued to change, and drive the flavor profile in their beers. Brooklyn Brewing’s Sorachi Ace exists as a perfect example: the grassy eponymous hops are a perfect complement for the yeast-driven flavor profile. These same hops in a normal ale or a traditional Lager would play annoying foil to our yeasty protagonist. In a yeast-forward Saison, they play plucky sidekick.

While it feels like style guidelines have been violated, Saison is continuing to do what Saison does: evolve, mutate, fit, flex, funk.

All of which is to say: these beautifully brewed and universally well-received beers might well be what was originally a spontaneously fermented beer with a simple recipe. One that sat around 3-3.5% ABV and morphed into a dry, relatively clean baseline style at 5.5-6%. From there, as it came Stateside, it morphed again, shifting back to its very early roots of being tart, if not wholly sour.

While it feels like style guidelines have been violated, Saison is continuing to do what Saison does: evolve, mutate, fit, flex, funk. Forever and ever, amen.

Boulevard Brewing Company’s Saison Brett quite unsurprisingly works Brettanomyces into its yeast profile, producing a tart-to-sour version of a still-dry and earthy saison. While the ABV is too high for what one of our ancestors might call Saison, the flavor profile is likely more similar than a clean interpretation. But, Saison Brett’s base beer, Tank 7, is Boulevard Brewmaster Steven Pauwels’ American take on a modern Saison, based on his experience and pedigree from his homeland of Belgium.


In Pauwels’ eyes, Saison in the U.S. has transitioned into place outside of its Belgian roots. “I wanted to brew Tank 7 because I saw other breweries making Saisons that were overly sweet or overly spiced,” says Pauwels. “I said to the team, ‘We need to make a Saison that’s more earth-like, more robust, more dirt-like.” This was the baseline thinking behind the original creation of Boulevard’s eventual #2 beer brand.

I wanted to brew Tank 7 because I saw other breweries making Saisons that were overly sweet or overly spiced. I said, ‘We need to make a Saison that’s more earth-like, more robust, more dirt-like.
— Steven Pauwels, Boulevard

“You shouldn’t have to chew on a Saison,” he adds. “It was a reaction to the movement of Saison in the U.S.”

Pauwels brought his yeast strain over from Belgium, but admits it’s “not a traditional Saison strain.” He describes his experience with Saison yeast in the same way many of us do, ever-changing, as if not just our tastes and palates shift, but the veritable essence of what the yeast creates does, too.

“Saison Dupont used to be so phenolic, but now it’s not. Either I have changed or it has changed,” Pauwels says of his love affair with the beer. “You need a good balance between ester and phenols. Nowadays there’s lot of Saisons out there with Brett, but they’re not all balanced.”

But even his description of his interpretation betrays the fluctuating nature of the beer: “we dry hop with Amarillo, Citra, and Calypso. It’s an American interpretation, we probably could have called it a Belgian IPA. For better or worse, there’s a weird perception to the style, people see farmhouse or Saison. In the beginning, Amarillo was the most funky hop you could get—you never knew what you were going to get.”

Pauwels of all people has the credibility to define Saison, but even still, he comes up with a definition that doesn’t jive with Markowski’s, nor with some of the most popular commercial examples. The only thing that goes steady is the idea that the yeast is in the driver’s seat.

“If I go back to brewing in Belgium, what sets Belgian beer apart from American beers is that Belgian beers are all yeast-driven,” he says. “I didn’t know squat about hops when I came to the U.S. When you look at it, you know what the priority is. Most important [is] hops, then water, than barley, then yeast. You talk to a Belgian brewer? It’s yeast, malt, water, hops.”

It feels sacrilege, in a beer-geek landscape where Belgium is Mecca, and Belgian beer the Kaaba, to think that young drinkers, encountering their first Saison, might consider it an American Saison the epitome of the style. But yeast is as yeast does, and an American version is, in theory, just as legitimate as the originals that fermented centuries ago in Wallonia. While the flavor profiles of the style have fluctuated with wild abandon, evolution dictates that such behavior is perfectly normal, if not in some ways, preferred.

Just imagine what we’ll be calling a Saison in a hundred years.

Words, Oliver Gray
Illustrations by Danielle Deley