Because there was so little room for pig rearing within the city walls, animals were imported, sometimes from far away. When the local region could no longer offer the quality and quantity necessary, the city began to import from areas known for their pork production such as Bohemia, Poland and Hungary.
In 1891, the largest slaughterhouse in northern Bavaria opened in Nuremberg. Today, Nuremberg bratwurst producers are allowed to purchase their pork from the supplier that offers the quality necessary. Other key ingredients - sheep's guts, salt, majoram, pepper and other spices - also come from outside of Nuremberg. This too has historical roots in the import and export of products from the orient (via Venice) that took place in the city in the Middle Ages and Renaissance.
The bratwurst's recognition in 2003 as a European Union product of Protected Geographical Indication (PGI) protects the knowledge, competence and long tradition of production of sausages within Nuremberg from producers lacking these skills. To receive this protection, all production of the Nuremberg bratwurst must take place within the city limits.