Exploring sour beer styles means diving into the world of Belgian - style
fruit lambic, also known as kriek, a spontaneously fermented beer brewed with fruit.
Almost all beer styles use domesticated yeast strains called Saccharomyces, and although there are long - established styles based on Brettanomyces — the
fruit - backed Belgian
lambics, for example — brewers tend to think of Bretts as mistakes, bad things that happened when you didn't control your tanks and barrels.