A Ferengi soft drink and the main commercial rival of Slug-o-Cola, mentioned when the beverage magnate Nilva visits Deep Space 9 in the episode Profit and Lace.
Eelwasser is a mass-market Ferengi beverage that competes with Slug-o-Cola for the thirst of the Ferengi Alliance.
It is mentioned in the Deep Space Nine episode Profit and Lace, set in 2374. Nilva, chairman of Slug-o-Cola and an influential commissioner of the Ferengi Commerce Authority, comes to the station to meet the female financial adviser Grand Nagus Zek has been boasting about. Quark, surgically disguised as the female Lumba, wins him over partly by talking shop about the cola trade and how to take customers away from Eelwasser.
The drink is never seen on screen, but together with Slug-o-Cola it sketches a Ferengi consumer culture built on slimy ingredients and aggressive advertising.