Ketwurst is a form of hot dog created in the German Democratic Republic. The word "Ketwurst" comes from a combination of Ketchup and Wurst .
Its preparation involves the heating of a special Bockwurst, larger than regular hot dogs, in water. A long roll is pierced by a hot metal cylinder, which creates an appropriate sized hole. The sausage is then dunked in ketchup and put inside of the roll.
The Ketwurst was invented at the State Gastronomical Research Center — like the Grilletta, a hamburger-like meatball-in-a-bun — around 1977–1978. At that time, restaurants at the Berlin TV Tower were incapable of handling the large numbers of visitors, so a take-away food was needed. It is often considered the archetypical East German fast food, but until German reunification, it was actually rarely seen outside the Berlin city center.