"In the 16th century... a microscopic stowaway somehow made its way to the caves and monasteries of Bavaria."

"The stowaway, yeast that may have been transported from a distant shore on a piece of wood or in the stomach of a fruit fly, was destined for great things. The newfound yeast fused with a distant relative, Saccharomyces cerevisiae, which was used for millennia to make leavened bread and fermented wine and ale. The resulting hybrid, representing a marriage of species as evolutionarily separated as humans and chickens, would give us lager, the clear, cold-fermented beer first brewed by 16th century Bavarians."

Scientists have finally identified the wild yeast, Saccharomyces eubayanus, and solved the age-old mystery of lager beer.