A few years ago the big talk in the craft beer industry was about how hoppy a beer could be. Every craft brewer was making IPAs, session IPAs, and imperial double IPAs. It quickly got to the point where there was an over-saturation of hoppy beers. Soon, brewers started to look to other types of beers to set themselves apart. This is when the latest beer trend started to gain footing. Brewers started to make sour tasting beers. Sour beers have actually been around for hundreds of years but had waned in popularity toward the end of the 19th century. So, for many beer drinkers, this was like tasting a beer they had never had before.
In the late 19th century, Louis Pasteur made discoveries regarding yeast and how it helps ferment alcohol. Before this, almost all beers had some sort of sour taste to them because they used “wild yeasts” that lived in the wood and air that the beer was being fermented in. Once Pasteur made his discoveries, it led to brewers picking and choosing the yeast for their beer, which then led to consistent flavors that could be produced over and over again After a while, this led to a decline in sour beers as wild yeasts were no longer needed to ferment beer. So recently, when brewers wanted something different from the hoppy beers, they turned to this old style.
There are a few different types of sour beers that will be highlighted throughout this story. These types include American Wild Ale, Berliner Weisse, Flanders Red Ale, Gose, Lambic, and Oud Bruin.
American Wild Ales are beers that are introduced to “wild” yeast or bacteria, such as Brettanomyces, Pediococcus, or Lactobacillus. This introduction may occur from oak barrels that have been previously inoculated, pitched into the beer, or gained from various “sour mash” techniques. A great example of an American Wild Ale is Riserva from Weyerbacher. Riserva is fermented with a blend of Saccharomyces yeast, Brettanomyces yeast, and lactic acid bacteria that produces funky, sour, and fruity flavors and aromas.
Berliner Weisse is a top-fermented, bottle conditioned wheat beer, made with both traditional warm-fermenting yeasts and lactobacillus culture. They have a rapidly vanishing head and a clear, pale golden straw-colored appearance. The taste is refreshing, tart, sour, and acidic, with a lemony-citric fruit sharpness and almost no hop bitterness.
Flanders Reds are commonly referred to as the “red” beers of West Flanders. Belgian Red beers are typically light-bodied brews with reddish-brown colors. They are infamous for their distinct sharp, fruity, sour, and tart flavors that are produced by special yeast strains. Very complex beers, they are produced under the age-old tradition of long-term cask aging in oak and the blending of young and old beers.
Gose is an unfiltered wheat beer made with 50-60% malted wheat, which creates a cloudy yellow color and provides a refreshing crispness and twang. A Gose will have a low hop bitterness, a complementary dryness and spiciness from the use of ground coriander seeds, and a sharpness from the addition of salt.
Lambic beer is a spontaneous fermented unblended ale that is indigenous to the Senne Valley of Belgium. Large portions of wheat bring out the crispness though the flavor is dominated by a unique tartness from the wild yeast and bacteria that inoculate the brew from both airborne and tainted barrels that they ferment in. An example of a lambic beer would be Up Ship Kriek from Revival in Rhode Island. This Lambic-style sour was created from wild fermentation in locally sourced wine barrels with tart cherries. Azacca hops make this pale and aromatic brew the perfect sipper for rebellious behavior.
Oud Bruins, not restricted to but concentrated in Flanders, are light to medium-bodied and deep copper to brown in color. They are extremely varied, characterized by a slight vinegar or lactic sourness and spiciness to smooth and sweet. A fruity-estery character is apparent with no hop flavor or aroma. Monomoy Kriek from Cisco is a great example of this style. This is a sour Flemish-style Red from Cisco’s “The Woods” series. It’s aged on whole sour cherries and in oak barrels.
Sour, wild, wood-aged beers are anything but boring. Their unpredictability can be unnerving. So many more of nature’s variables are at play during fermentation and maturation; the brewer is dealing with complex ecosystems, not a straightforward industrial process. But beer lovers who embrace these new interpretations are finding flavors that stretch our modern definition of “beer”—and remind us of its origins.