Sausages are rarely composed of just meat. Spices, non-meat fillers, binders, and colorings are often used in
sausage formulae. Red coloring, for instance, was standard in hot dogs until
the 1970s and some regional American brands still use it. This one is for a
sausage that would be seen as unappetizing in its “natural” state.
From: Butchers’ Packers’ and Sausage Makers’ Red Book. Sayers, George Jacob. Chicago: Wolf, Sayer & Heller. 1913. Crerar Collection: 689.13 R300.