Lesson 6: All Mixed Up
Prior to technological advancements in the mid-nineteenth century, all beer was to some degree, sour. Poor sanitation and naturally occurring yeasts and bacteria were to blame for infecting beer, giving it an undesirable sour quality. The advent of pasteurization and refrigeration really changed the beer game, allowing for clean, crisp beers to take the main stage. Although it’s a time-honoured tradition in Belgium, the demand for sour beer is a relatively new concept in North America. In craft brewing today, sours are generally made through a process called mixed-fermentation. As opposed to single-culture fermentation, where a single strain of yeast …