Brandon Woodruff likes to say that he makes “really good bad beer.” There’s some truth in this. The beer that he makes as head brewer at Manifest Beer Company eschews modern convention. All beer is made by boiling malted grains, barley, and often hops into a thick, sweet liquid called a wort. In modern breweries this wort is transferred boiling hot —and thus sterile— to an airtight container where it is cooled and inoculated with a single strain of yeast.
Total control over the fermentation lends consistency. But this process has only been around for about 150 years. Louis Pasteur developed his theory of fermentation in the 1870s and previously the process by which wort turned to beer was not well understood.
Historically, the wort would be inoculated by some other source. That could be leftover yeast on the inside of barrels or even ambient microbes in the brewery. “The Vikings,” Woodruff says, “had a stick in each family that they would use to make their beer. When there was a marriage each family would give a part of their fermenting stick. That way the new couple’s beer would be a mix of both families.” Woodruff keeps this tradition alive by saving and reusing old barrel staves to start new fermentations.
This wild or spontaneous brewing process produces results totally unlike conventional brewing. Where conventional fermentations use a yeast monoculture, wild fermentation always uses a mix of microorganisms.
The most common three are Lactobacillus, Pediococcus, and Brettanomyces. Lactobacillus, produces lactic acid which gives beer a taste that Woodruff describes as, “a face puckering mouth watering sour.” The lactic acid also plays a crucial role in the fermentation process. Without airtight containers there is a risk that E. coli and other harmful bacteria will grow in the wort. Fortunately, the lactic acid drops the pH to between three and four, a range too acidic for E. coli but ideal for Lactobacillus and it’s partners.
Once conditions are right Brettanomyces yeast can be introduced. Brettanomyces does most of the actual alcohol production. It also produces a wide range of complex flavors broadly referred to as funk. Woodruff compares these flavors to the smells of a barnyard “Horse leather and hay, like it smelled on my grandmother’s farm,” he says. “You can really only get those flavors with Brettanomyces.”
Pediococcus is the most maligned of the three. A frequent contaminant in conventional fermentations of beer and wine it generates flavors ranging from popcorn butter to vinegar. Woodruff, like many wild fermenters, believes that pediococcus produces some of the best beer you can get, but it takes time for the flavors to mature. “For the first three months the wort is just this ropey slime, but eventually it breaks down and after about six months you have this amazing funk.”
The wild fermented product is usually blended with beer made using the same wort but fermented using Brettanomyces alone in order to manage the levels of funky flavors that are produced. For Woodruff the blending process is one of the best parts of the job, “We make a perfect little marriage because it might be too funky if its not blended back. Finding those correct levels of funk and non funk is the fun part. It involves a lot of drinking that day.”