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The dish is named for the Prussian city of Königsberg (now Kaliningrad) and is one of the highlights of East Prussian cuisine. In the German Democratic Republic (GDR), the dish was officially called Kochklopse ("boiled meatballs") to avoid any reference to its namesake city, which in the aftermath of World War II had been annexed to the Soviet Union. The city's German inhabitants had been expelled, and the city had been repopulated with Russians and renamed after a close ally of Joseph Stalin in the Soviet leadership. The GDR forbade using the historic names of the annexed territories or cities. Königsberger Klopse were jokingly referred to as Revanchistenklopse.
The meatballs are made from very finely ground veal, though less expensive beef or pork is often substituted), along with onions, eggs, and spices, chiefly white pepper). The traditional recipe uses anchovy. If herring is substituted, the dish is called Rostocker Klopse. If both anchovy and herring are omitted, it is called Soßklopse.
The meatballs are carefully simmered in salt water, and the resulting broth is mixed with roux, cream, and egg yolk to which capers are added. A simpler version of the recipe thickens the sauce with flour or starch only, omitting the egg yolk. A refined version uses only egg yolk as a thickener. Capers are an essential ingredient in all these versions.