"Mountain Dew" used to refer to illegally distilled liquor, or moonshine. Today, though, the phrase is associated with a line of sweet, caffeinated beverages made and distributed by PepsiCo – and very much legally. The name comes from the inventors, a pair of Tennessee bottlers who were searching for the perfect mixer. In the years since they first concocted Mountain Dew, their citrus-flavored soft drink has become one of the most popular sodas in the world.