BEER: A Wild, Wild Tale

Updated: Mar 28, 2020

As the name suggests, wild ales, are the free spirits of beer; they can be fruity and they can be bold, they can be light and they can be viscous, and they can be, generally, hard to categorize. So what does this spectrum actually mean? There is, most likely, a wild ale for you. —INGRAIN, Summer 2018

American wild style craft beer

Wild ales are complicated. Even the descriptions (phrases like “tends to” and “not necessarily” are common) for the American Wild Ales category in the Beer Judge Certification Program (BJCP) read like a verbal interpretation of the “throwing your hands up” meme (you’ll want to join in and throw a stack of papers in the air in frustration). After all, the BJCP is the beacon for beer style guidelines. And yet it seems the folks there have as many questions regarding the style as those of us seeking answers.

To be fair, American-style wild ales are not easy to categorize. To the everyday beer drinker, they’re widely known by the misnomer sour beers, and yet these beers can exhibit a multitude of characteristics. Some are light and effervescent; others may be more tart and bold or almost wine-like. “Expressive” may be the one unifying word to justly describe them. To better understand today’s American Wild Ales, it helps to first take a step back and look at their lineage.


American-style wild ales are descendants of farmhouse ales, which fall on the more traditional side of the beer spectrum; think Saison, bière de garde (beer to keep or store), and Sahti (Finnish-style ale brewed with juniper branches). As the name implies, farmhouse ales were beers made using the ingredients grown on brewers’ farms (a common practice throughout France and Belgium). Beer history geeks tell romantic tales of seasonal farmhands choosing where to work based on the quality of the beers at their potential place of employment; a ration of beer was considered part of a brewing assistant’s wages. Those must have been some mighty fine ales.

Not surprisingly, farmhouse breweries were not completely sterile environments. Local friendly bacteria and wild yeasts favorably affected the fermentation process, creating the same layered dimensions of flavor that modern breweries still covet. Today, some of these ages-old yeasts (including Brettanomyces, the most common) are reproduced in laboratory and brewery settings, but they still provide uniquely wild ale attributes to modern brews.


The physical introduction of bacteria and wild yeast strains, other than traditional brewer’s yeasts used during fermentation, is what makes a beer, according to BJCP categories, truly an American Wild Ale. The unique bacteria and cultivated “wild” yeasts that the brewer chooses each add complexity and unique flavor characteristics to the beer. For example, bacteria such as Lactobacillus and Pediococcus introduce tartness, whereas a yeast like Brettanomyces offers depth and qualities reminiscent of leather, hay, and earthiness.


Today, American-style wild ales begin with either a “base” beer or the wort for a base beer that has yet to be fermented. Though farmhouse-style ales are very common, essentially any beer style—brown ales to wheat beers, light to dark beers, and even hoppy or malty beers—can be used as the base.

Common additions to the base beer include “adjuncts” (industry-speak for ingredients beyond hops, malt, yeast, and grain) such as fruits and spices that are used as flavorings. In some instances, fruit is added simply to aid in fermentation (the fruit skins “capture” and contain natural wild, airborne yeasts). Regardless of the base beer or adjuncts, what makes these beers technically American Wild Ales by BJCP standards is the introduction of bacteria and truly wild or cultivated “wild” yeasts.

American-style wild ales are often polarizing—coveted at one end of the bar and misunderstood at the other. These beers offer up such a broad range of characteristics (from light and fruity to viscous and bold), we are of the mindset that this is a simply tasting dilemma. If haven’t found one you like, you probably haven’t found the right ale.

The bacteria and truly wild (or cultivated “wild”) yeasts needed to brew an American-style wild ale today can be introduced during either the primary or secondary fermentation stages. If added during the primary stage, the brewer will forgo using a standard brewer’s yeast altogether (for American-style wild ales, Saccharomyces cerevisiae, commonly known as ale yeast, is often the preferred standard yeast). When the bacteria and “wild” yeast are introduced during the secondary stage, brewer’s yeast is still utilized during the primary brewing stage.

The early introduction of bacteria and “wild” yeasts tends to produce more pronounced sour or tart flavor notes; when added later, these same characteristics tend to be more subtle (much of the wort sugars have already been consumed during the fermentation process). Timing also affects the flavor and overall characteristics of the finished beer. If fruits are incorporated, they are typically added during the secondary stage of fermentation to provide yet another layer of character complexity.


Used for centuries by Belgian brewers, coolships (koelschips in Flemish) are increasingly being used by American-style wild ale producers. These vast fermentation vessels are shaped like giant copper or stainless steel square baking pans. The open format and large surface area allow the wort to cool while collecting ambient yeast and microflora from the surrounding environment, which offers an even more unique layer of complexity for the beers.


Breweries that produce a significant quantity of American Wild Ales often opt for wooden casks to house the beer during the fermentation process and for aging the beer. (Wood is the ideal host for the living bacteria and souring microorganisms that give wild ales their distinct characteristics.) Wine barrels, once the preferred fermentation vessel for American-style wild ales, increasingly share barrel warehouse space with larger oak vats called foudres (wooden vats traditionally used to age French wine like Bordeaux) and other wood aging vessels like barrels used to age spirits.

Though typically flavor-neutral, barrels may also be chosen to imbue subtle flavor and aroma characteristics into the beer (such as barrels recently used to age stronger spirits like whiskey). In some instances, friendly bacteria are introduced again during the bottling stage so the beer continues to develop as it ages; the bacteria also aide in shelf stability.

American-style wild ales are often polarizing—coveted at one end of the bar and misunderstood at the other. These beers offer up such a broad range of characteristics (from light and fruity to viscous and bold), we are of the mindset that this is simply a tasting dilemma. If haven’t found one you like, you probably haven’t found the right ale.


American wild style craft beer

American wild style craft beer

Want more beer history? Check out our Beer section.

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