The sausage is made in a cylinder shape, 1 1/2 to 2 inches (4 to 5 cm) wide.
Inside, the sausage is bright red with white splodges from the lard in it, and black dots from the pepper.
It is made from pigs that are fed only dry feed. They are slaughtered when they weigh between 285 and 33 pounds (130 and 150 kg.) The sausage is made from lean trimmings from the ribs, shoulder, thigh and belly. The meat is minced finely, and mixed with fat from the throat.
The only flavouring is coarsely ground pepper, sliced garlic and wine.
The sausage is first matured in a warm room heated by fire in a fireplace using olive and White Thorn wood, then moved to a cold room for aging 3 to 4 months. The final product will weigh between 1 3/4 and 6 1/2 pounds (.8 and 3 kg.)
It is traditionally made November through to March. It is mostly made just commercially now. Commercial makers make it most of the year.
Mortadella Viterbese is often served as part of a mixed cold cuts plate, though it is not always identified by name.
The Touring Club Italiano guide of 1931 cited Mortadella Viterbese as a a product typical of the area.