We have a strong passion for brewing mixed-fermentations beers. While we fully intend to wrote many of our own stories about our beers and how we brew them, we wanted to give you a quick lesson on what this means. So we decided to turn to one of our main inspirations, Milk the Funk.
Mixed fermentation (also referred to as “mixed culture fermentation”) is any fermentation that consists of a combination of Saccharomyces (brewer’s yeast), Brettanomyces (wild yeast), Lactobacillus (lactic acid bacteria), and Pediococcus (lactic acid bacteria), or other microbes that are unconventional in brewing. Broadly speaking, there are two styles of mixed fermentations: mixed fermentations with lactic acid bacteria (Lactobacillus and/or Pediococcus) and mixed fermentations without lactic acid bacteria. Mixed fermentation sour beers are characterized by their higher acidity and tart flavor caused by the production of lactic acid, and require the use of a lactic acid bacteria (abbreviated as LAB; generally Lactobacillus and/or Pediococcus). These beers generally fall within a pH range of 3.0-3.7 (although Titratable Acidity is more accurate for measuring perceived sourness). Mixed fermentation without lactic acid bacteria are usually fermented with a combination of Saccharomyces and Brettanomyces. Mixed fermentation beers without lactic acid bacteria may be slightly tart from the acetic acid production of Brettanomyces, but are generally not considered to be sour if well brewed because they lack lactic acid and too much acetic acid is considered a flaw. For both categories, the primary fermentation will be completed by yeasts such as Saccharomyces and/or Brettanomyces.