Those of us fortunate enough to have experienced the North American beer renaissance would never have imagined anything like this in the 1970s. But there was no stopping the growth of craft beer once the ball was rolling . Now that growth has taken us from a foundation of British, German and Czech classics through an era of extreme beer and barrel aging and into the cutting-edge realm of wild beers.
The North American tapestry is colorful. Devotees of wild beers will instantly recognize the earmarks of lambics and Flemish beers, but there are contributing features from other extinct and modern styles. These wild brews are not specifically a style as much as a philosophy. Summoning the many elements used to ferment beer throughout history, wild brewers offer a kaleidoscope of products. In just a short time, the ride has already been a wild and exhilarating one, and certainly there is no shortage of eager customers.
Not long ago, wild beer was considered beyond the realm of North American brewers. It was thought to be impossible to recreate centuries of European conditions; brewers dreaded the prospect of inviting the malicious microbes needed to make wild beers into the brewery. A bold and risky undertaking perhaps, but a few trailblazers were up for the task—equal parts mad scientist, brewing scholar, microbiological police officer and artisan.
The development of laboratory methods 150 years ago for isolating, cultivating and sustaining pure yeast strains was among the most important advances in brewing. Gone were troublesome wild yeasts and bacteria. But some brewers, thankfully, preferred a bit of nature in their beer, dismissing the refinement as boring and detached from stylistic roots. Some of these brews have persevered, such as the sours of Flanders and lambics, which many new wild beers are based on. And from a historical perspective, barrel-aged stock ales of 18th- and 19th-century England are also excellent prototypes.
The red and brown beers of Flanders are produced today with standard top-fermenting yeast glorified by additional fermentation and aging with one of three kinds of bacteria. Traditional lambics, on the other hand, are undomesticated beers, gaining unmatched complexity through spontaneous fermentation, aging and exposure to microflora that inhabit wooden casks. Another influential historical beer is English stock ale, the well-aged strong ale of Georgian and Victorian England that inherited stale character from their casks. It is from one of these casks that the brettanomyces yeast was isolated. Very important to the boom of English brewing history, this wildness was winnowed out of the product as brewers moved to other bacteria and nonporous materials for fermentation and maturation.
The Rogue Gallery
North American brewers use the term wild somewhat liberally by purist Belgian lambic standards, though it is perfectly acceptable in nouveau microbrewing. A few brewers allow ambient organisms to settle into the cooling wort as the lambic brewers do and use inoculation with unconventional organisms. The main unconventional players are brett yeasts, and bacteria from the genera lactobacillus, pediococcus, and acetobacter. Brewers use carefully selected singular or multiple cultures and make important decisions on when to add them. They can be introduced at the primary or secondary stage. Alternatively, brewers can inoculate porous vessels used for fermenting or maturation to kick-start a spontaneous fermentation. They can influence the primary character, a secondary highlight or a background note. Fermentation generally involves traditional saccharomyces fermentation augmented by untamed organisms.
Brettanomyces, of which there are four commercial strains, may be the most commonly used organism with unlikely adjectives: Musty, moldy, horse blanket, barnyard, leather and sweaty are but a few. Oddly delicious, these funky components fit seamlessly in a well-made wild. Some are potently influential, while others are mildly so. Some brewers have taken the bold move of making a brett-only fermented beer, even employing both primary and secondary/maturation strains. Brett thrives after saccharomyces has finished its job, chewing up sugars that the latter is simply incapable of.
The next most commonly used untraditional organisms are the lactobacilli, those bugs responsible for the sharp and unmistakable lactic acid sourness found in Flemish sours and lambics, and the signature of Berliner Weisse. Fairly one-dimensional in character, they coexist nicely with brett, providing an intense counterpoint to the musty, damp notes. Pediococcus is used to a lesser degree, mainly for additional complexity, variability and uniqueness, or a closer approximation to the lambics or Flanders sours. Pediococcus is also a lactic acid producer, but offers depth that lactobacillus does not. The final, and least common, among the main uncultivated organisms is acetobacter, producer of acetic acid (vinegar) and a common bacterium found in lambic and Flemish beers. The acetobacter influence is best used as a complementary note. Wild beers heavy on lactobacillus, pediococcus and acetobacter are often referred to as sours.
The range of beers produced via wild fermentation is broad, but many are designed to emulate the Flanders sours and lambic, with the former being easier to create and the latter almost impossible. On the other hand, brewers are just as likely to infuse more traditional Belgian styles with feral organisms, creating a whole new genre of beers. Brown ales, resembling Belgian dubbels or quads, seem quite popular — the dark fruit, spicy and rummy nature marrying well with both sour and musty character. Golden ales and blonds are also well-represented, as are Belgian farmhouse-style brews, presenting a more austere expression of the wildness. A currently hot style, Belgian IPA, is sometimes made with a wild brett edge. Perhaps more black beers will find their wild side in the future.
To the earlier point of style, wild ales are all about fermentation and the influence of eccentric organisms. Most are sold in bottles, sequestering these wild characteristics and allowing them to work for long periods of bottle aging. Wild fermentation is sublime in the hands of a skilled brewer, and these beers can be enhanced further by aging in wine or spirit barrels.
North American brewers have always done things their own way, unafraid of the unknown. Perhaps they are beginning to carve out a legacy that emulates the Belgians’. There is a small cadre of breweries known for their wild offerings. Some are pioneers, and all are torchbearers. They are products of the microbrewing scene and have immersed themselves in this quirky corner of the market. Hardly reckless, they are well-schooled and inquisitive.
It will be quite interesting to see other inspirations this genre spawns. Certainly, the promise is great. There is no doubt that beer lovers are fully onboard. Calling these beers wild is not only appropriate, but also a fitting metaphor for the brewers who make them. These are wild times indeed.