Researchers believe they have finally identified the variety of wild yeast that now underpins the entire lager beer industry.
In the 15th century, the wild yeast travelled more than 10,000km from South America to Europe, attached to a piece of wood or in the stomach of fruit fly.
Once in Europe, the stowaway yeast fused with a distant cousin, forming the organism responsible for fermentation in lager beer.
Read more at University of Wisconsin-Madison