The primary meat in a traditional frankfurter is pork. The original Frankfurter Würstchen from Frankfurt, Germany, was made from pure pork and was traditionally stuffed into sheep-intestine casings before low-temperature smoking.
Frankfurter sausages have medieval roots in Frankfurt and were associated with the city’s civic and imperial celebrations. Their golden color and characteristic flavor came from smoking, while gentle heating in hot water helped prevent the casing from bursting.
A common mix-up comes from Vienna. In 1805, butcher Johann Georg Lahner is said to have adapted the Frankfurt sausage in Vienna by combining pork and beef. In Austria, that style is known as a Frankfurter, while the original Frankfurt version remains pork-only. Modern hot dogs can also contain beef, chicken, turkey, or blends, but those are not the traditional pork frankfurter.