Hubert Erzmann, a 75-year-old hobby historian, discovered the oldest known recipe for Thuringian bratwurst last month, while doing research at an archive in the eastern German town of Weimar.
The guidelines, which date back to 1432, were written in pen and ink on a heavy, yellowed parchment. They describe what should go into a sausage -- and what most definitely should not.
Only "pure, fresh meat" should be used, according to the recipe, which is written in an early form of German. The meat should not be wormy, pustuled or otherwise diseased, nor going rancid or moldy.
Also disallowed in the mix of ground meats and spices, which when combined make one of Germany's most famous street snacks, are "appendix, heart, kidney" as well as "any other dangerous or foreign meat."
Anyone caught stuffing undesirables into his several meters of gut casing risked being fined "two current shillings (24 pfennigs)" per offending wiener.
Experts say it is hard to know just how serious a penalty that would have been at the time, although information available at the First German Bratwurst Museum, near the eastern German town of Erfurt, implies it was probably not ruinous, and could be equivalent to a day's wages.
Meanwhile, the unearthed recipe has taken pride of place among the other fascinating bits of bratwurst history on view at the Bratwurst Museum.
These include the notation that a certain Hans Stromer ate 28,000 wursts between 1517 and 1592 while locked up in jail; a record of a 670-meter (nearly half a mile) long bratwurst made in 1600; and the fact that in 1800, Goethe was so impressed by some "deliciously prepared" Thuringer Bratwurst made with marjoram, that he mailed some from Nuremberg to all the way home to Weimar.