It’s a clear, crisp mid-December afternoon. I’m driving from Columbus to Athens with my wife Laurinda and our friends Ralph and Lucy Wolfe. We’re on our way to a special event being held this evening at Little Fish Brewing Company. They’ve opened a limited number of spaces for people to observe the first stage of brewing of a spontaneously fermented beer. Not many breweries attempt to brew beer using this old-world approach, and for good reason. It’s an unpredictable, slow way of making beer, but when it all comes together the final product can be so interesting. I’ve been lucky enough to visit a few breweries that either specialize in or dabble with spontaneous fermentation, but never on a brew day. It’s a rare opportunity and I figured there would be like-minded people out there who would be interested to tag along vicariously.
A Primer on Spontaneous Fermentation
Of all the steps that go into making a beer, I would argue that the most critical is introducing yeast to ferment the sweet, sugary solution brewers call wort. As the saying goes, brewers make wort but yeast make beer. Not only do different yeasts have different characteristics and impart different flavors, the environment is full of microbes that would love to feast on batch of freshly brewed wort. Many of the microorganisms that float around in the air produce flavors that are pretty unpalatable, so it’s no wonder that almost all brewers choose what yeast does the fermentation and go to great lengths to exclude all other microbes. When a brewer chooses to make beer using spontaneous fermentation, they throw all of that out the window. Instead of pitching commercial yeast, the wort is left exposed to ambient air so that wild airborne yeast and bacteria can take up residence.
Long before scientists like Pasteur and Hansen developed a scientific understanding of yeast, brewers developed practices to incorporate yeast from previous batches. For reasons unknown to this author, the brewers who made lambic beer in the Senne River valley in and around Brussels chose to use spontaneous fermentation rather than repitching their house yeast. At one time there were hundreds of breweries in the region that practiced this tradition, and though the number of lambic breweries dropped precipitously during the 20th century, a handful persevered. By the end of the century, the surviving lambic producers were the last practitioners of spontaneous fermentation. This led some to assume there was something special about the air around Brussels that made it uniquely suited for successful spontaneous fermentation. It turns out that idea is completely false, as several adventurous American breweries have shown over the past 10-15 years. Allagash was the first American brewery to try their hand at spontaneous fermentation. While this was only a side project at Allagash, later entrants like Jester King (Austin, Texas) made spontaneous beers more of a signature focus, while others like De Garde Brewing (Tillamook, Oregon) and the now defunct Black Project (Denver, Colorado) went all-in on spontaneous fermentation. Despite the efforts of these pioneers, only a tiny, tiny fraction of the 10,000 or so US breweries practice spontaneous fermentation. I’m not aware of an Ohio brewery other than Little Fish that is pursuing it.
Lambic beer, like champagne, is an appellation. By EU law only those breweries using traditional methods and brewing in the Senne River valley near Brussels can call their beer lambic. The methods surrounding lambic beer are governed by the High Council for Artisanal Lambic Beers (HORAL), a non-profit organization made up of Belgian lambic producers. To be called a lambic, a beer must meet more stringent requirements than just spontaneous fermentation and geography. The malt bill must contain at least 30% (unmalted) wheat. Though not strictly required, most lambic brewers use hops that are aged for years to minimize their aroma and flavor contributions, while retaining their antimicrobial properties. Most exported lambic beer is actually a blend of beers that have been aged for different lengths of time and is called geuze (Flemish spelling) or gueuze (French spelling). If the beer is to be called oud geuze or vieille gueuze (oud/vieille meaning “old” in English) it must meet further requirements. The beer must contain some fraction that has been aged in wooden barrels for at least three years, and the weighted average age of the blend must be at least one year old. The beer must undergo a secondary fermentation in the bottle and must be aged for at least 6 months after bottling. If you’ve had one of the sweeter lambics, for example Lindemans Framboise, it would not meet the requirements of being called an oud lambic. To maintain that level of sweetness, the beer must be pasteurized at some point to keep the yeast from consuming the sugar. Hence the beer would not meet the bottle conditioning requirements needed to use the descriptor oud. There are some other technical details, but this should give you an idea of the rules and regulations surrounding lambic beer.
If you are interested in a closer look at the Belgian lambic tradition I would direct you to an article I wrote some years ago after visiting Cantillon and Drie Fonteinen, called Adventures in Lambic Land.
Spontaneous Fermentation at Little Fish
Ohio is home to many charming small towns, but for my money none better than Athens. Nestled in the foothills of the Appalachian Mountains, the surrounding countryside is hilly and forested, not unlike the Ardennes region of eastern Belgium. The presence of Ohio University effectively doubles the population when the students are in town and gives Athens a vibrancy that similarly size towns often lack. Little Fish is located a couple of miles west of downtown, near a bend in the Hocking River. When we arrive a few minutes after 5 pm, it’s past sunset but not fully dark outside. The brewery is silhouetted by the last rays of the setting sun. Upon entering the taproom we are greeted by Sean White, co-founder, head brewer, and the driving force behind the spontaneous beer efforts at Little Fish.
We sit down for dinner and a beer before the event starts. Appalachian Spontaneous Ale, Batch 1 is on tap, but since we’ll get to try that beer later, I opt for something different. Little Fish is best known for their line of sour and farmhouse beers, with four GABF/WBC medals to show for it, but if you visit the taproom you’ll find a wide range of styles on offer. I order a glass of Karmanfest, a malt-forward märzen-style beer. Despite the allure of the house burger or one of their pizzas, I order the nuts and greens salad for dinner, along with an order of crispy brussel sprouts as an appetizer. It’s not the subject of this story, but the food at Little Fish is excellent. The kitchen is run by Becky Clark, who has been nominated for a prestigious James Beard Award for her work at Little Fish. Like the beers, the menu leans hard into locally sourced, fresh ingredients. If you only take one thing away from this story, it would be to order food the next time you visit the taproom, and don’t forget to include an order of brussel sprouts.
Shortly after dinner, the 20 or so people who have come for the event move into the back part of the brewery. Sean starts the evening by explaining the lambic beer tradition and the aspects of that tradition that are followed at Little Fish. Points of similarity with the lambic breweries of Belgium include:
- A malt bill that consists of 30% unmalted wheat and 70% undermodified barley (pale ale) malts from Haus Malts in Cleveland
- The use of whole-cone hops that have been aging in the attic of the brewery for at least three years, if not longer
- A three hour boil
One aspect of the traditional process that Little Fish initially adopted but have since moved away from is the turbid mash. This process involves a rather complicated series of rests during the mashing process when enzymes in the barley convert starches to sugars (click here for more details on turbid mashing). Sean tells us that several studies have shown that the goal of producing a dextrinous wort can be achieved with a simpler single infusion mash, knocking a few hours off the brew day.
At this point in the evening, a couple of bottles of Little Fish’s Appalachian Spontaneous Ale, Batch 1 are opened. This beer was brewed in February 2019 and aged in an oak puncheon for 3.5 years before bottling. As discussed above, lambic geuze is traditionally made by blending 1-, 2-, and 3-year-old beers, but when you are trying to get your program up and running the blending options are limited. This beer came from a single 500 Liter (132 US gallons) oak puncheon, with only a small amount of fresher spontaneous beer blended in to provide a sufficient concentration of healthy microbes to bottle (or keg) condition the beer. It’s quite nice – moderate funk and fairly tart, wine-like fruitiness, accented by tannins from the oak barrels, effervescent with a thin vinous body – but given the lack of blending I think it would be fair to say it lacks the complexity that you would find in the best examples of a Belgian geuze.
Next, we crack open a couple of bottles from the next batch. This beer, named Estate Honey, was released only to members of Little Fish’s Wild and Local League. It was made from the same batch of beer, but from the other puncheon filled on that brew day back in 2019. It was aged a bit longer, over 4 years, and honey from the bee hives at Little Fish was used as the sugar source for bottle conditioning. This beer differs from Batch 1 in a couple of other ways. Wine yeast was added at bottling and the beer was packaged in green glass bottles. Sean feels the use of wine yeast seemed to lock in the sourness level present at bottling, whereas Batch 1 got more acidic after packaging. The use of green glass bottles lets in more light, and exposure to that light can cause the hops to develop some light-struck character, which in small quantities Sean favors in these types of beer. Upon tasting I would agree that this beer is not quite as sour as Batch 1, which is a good thing. If there is any light-struck hop flavor it’s below my taste threshold, which is not necessarily a bad thing.
After sharing a bottle of geuze from the highly respected Belgian Lambic brewery Drie Fonteinen, we make our way upstairs to the coolship room. The rectangular stainless steel coolship shown in the photos below is the centerpiece of the smallish room, as you would expect. Near the stairwell entrance a large oval-shaped decorative piece featuring the signs of the Zodiac hangs on the wall, while the opposite end features a garage door that can be opened up to let in more night air if needed (tonight it is not needed). A dozen or so reclaimed oak planks hang from ceiling above the coolship. Their purpose is to capture and nurture the yeast and bacteria that will lead to tasty beer. Once you move past the coolship, oak puncheons—large barrels made for the wine industry that can hold 500 L (132 US gallons) of liquid—are arranged in rows on either side of the room, eight puncheons in total. The batch of beer being brewed today is nominally 12 bbl (378 US gallons), though undoubtedly somewhat smaller after undergoing a three-hour boil. That quantity of wort is enough to fill two puncheons, with a little bit left over that is stored elsewhere and used later to top off the barrels.
Finally the moment we’ve been waiting for arrives. The brewers start transferring the amber-colored wort up to coolship and the room starts to fill with steam. Prior to the transfer, we open the windows on both sides of the room, so that we won’t be in full on sauna mode. The chilly, unheated room quickly warms as the room fills with steam coming off the wort. It takes a half an hour or so to transfer all of the wort upstairs to the coolship. In the meantime, we get to sample small tastes of beer from the puncheons that have been aging for 1, 2 and 3 years. The beers all seem to be heading in the right direction, with varying degrees of acidity and funk, and importantly no challenging off flavors. Sean is worried that the 3-year-old beer may have too much wine character from its puncheon, a reference to malic acid is thrown around, but it’s certainly not overwhelming and it seems to me that it might add more complexity to the blended finished product.
When the coolship is nearly full we make our way back downstairs to the taproom. If all goes to plan the wort will have cooled into the mid 60’s (on the Fahrenheit scale) and will be transferred into waiting puncheons in the morning. If the right yeast and bacteria have made it into the wort it will start fermenting in 7-10 days.
The Trials and Tribulations of Spontaneous Fermentation
It’s an understatement to say that this way of making beer comes with some risks. At one point in the evening Sean recounted the first batch of spontaneously fermented beer they made using the coolship. He compared the sensory of that beer to sticking your head into a ripe dumpster. There’s no saving something like that and the whole batch had to be dumped. In a later follow up email he expanded on the challenges of spontaneous fermentation:
“This is really early on so we are learning a lot and have a higher failure rate, but we are always pushing this in a direction that we believe will provide a consistent success rate. As a side note, the best people I have talked to in the industry STILL have a success rate of 25% dumpers, 50% blenders into other projects, and 25% good enough to keep as spontaneous, gueuze-type product. So, it’s always a gamble.”
We also discussed the lambic tradition of only brewing from late fall to early spring. This practice is typically justified because the concentration of unwanted microorganisms in the air is less when it’s cold outside. Perhaps there is some truth to that rationale, but Sean told us that he feels the most important factor is that it needs to be sufficiently cold outside to keep the barrels from getting too hot once the wort begins fermenting. Ideally the fermentation temperature would stay in the low to mid-60s. A few years ago they tried spontaneous fermentation in May, but that batch was a dumper and the experiment of brewing that late in the spring will not be revisited.
This is also a good time to dispel the myth that all of the desirable yeast and bacteria float in through the open windows on the night air. That’s not true in Athens any more than it is in Brussels or Portland, Maine or Tillamook, Oregon. Hence, the wooden planks hanging over the coolship that have been splashed with successful batches of spontaneously fermented beer. Back in 2020, Sean was a guest on the All Things Beer Podcast that I co-host. He is passionate about beer and the wide ranging conversation covered enough ground to warrant splitting into two episodes. If you’d like to learn more about this process I would strongly recommend giving them a listen, particularly episode 17 which is mostly about spontaneous fermentation (click for links to Episode 16 and Episode 17). In that conversation Sean mentions that he has a friend who unsuccessfully attempted spontaneous fermentation of a batch of homebrew while camping in the woods. Apparently there just isn’t a high enough concentration of good microorganisms to make decent beer in most wild places. Most of us would like to think that a a fruit orchard is the best place to inoculate your wort, but in reality the ideal place to find the right mix of microorganisms is a brewery that has successfully been making sour beers for some time.
Another strike against the romantic “pixie dust in the night air” description of spontaneous fermentation comes from Block 15 Brewing in Corvallis, Oregon. I was lucky enough to tour the brewery and interview co-founder Nick Arzner back in 2019. Their “coolship room” is in the basement of the downtown brewpub. There aren’t any windows to let in microbes from the surrounding Willamette River Valley, but they have sprayed bottles of the best sour beers on most of the wood surfaces in the basement. In my humble opinion, the spontaneous beers made at Block 15 are among the best I’ve tasted at any US brewery. You can read more about that trip in my story, Brewing Wild Ales in the Basement – A Visit to Block 15. If you are up for even more material on spontaneous fermentation you might also check out the story I wrote after visiting De Garde in Tillamook, Oregon in 2015: Wild on the Coast – A Visit to De Garde Brewing.
One final nugget of wisdom I picked up from Sean has to do with the pH of the wort. He told me they have been pre-acidifying wort to a pH of 4.7 using lactic acid, in an attempt to diminish the effect of enterobacter in the early stages of fermentation. Enterobacter is one of the first microbes to start fermenting spontaneous beer, but if you get too much of it, the batch will taste like garbage forever (that’s a direct quote). Sean feels that too much enterobacter is largely responsible for the failed batches at Little Fish. While pre-acidification is a more modern approach to spontaneous fermentation, it is practiced in Belgium. He has future plans to pre-acidify to the maximum allowable rate that lambic brewers use, pH = 4.4.
Closing Thoughts
It’s an understatement to say that launching a successful line of spontaneously fermented beer is an ambitious passion project. It’s also a long game. Little Fish started this journey back in late 2018 and only now are they getting to the point where they can do a proper blend of 1-, 2- and 3-year-old beers. Sean told me that we can expect to see a release of such a blend in 6-12 months. In the meantime Appalachian Spontaneous Ale, Batch 1, is available both on tap and in bottles at both the Athens and Dayton locations.
It’s a long, hard journey but it seems to me that Little Fish is on the right track. There’s so much that can go wrong with spontaneous fermentation, but the beers I tasted had the right characteristics – fruity, funky, tart, and vinous, without going over to the dark side. As the program matures they will be able to properly blend, and the beers should become more complex. As the coolship room gets further inoculated with the right mix of wild yeast and bacteria, the rate of batches that need to be dumped should decrease. As they hone their packaging techniques, they may be able to dial in the acidity to the desired levels. It may never be a profitable venture, but being able to pull this off gives a brewery an incredible amount of credibility, and that’s got to be worth something. I for one am thankful that an Ohio brewery is willing to give this a go and I wish Sean and the whole team at Little Fish all the best in this ambitious endeavor.
Pat's Pints 
Leave a comment