Suomen Sillikonttori´s Mustard Baltic Herring is manufactured from Baltic herring caught in the Bothian Sea from a MSC-certified sustainable fishery. Baltic herring is filleted and marinated in barrels in the fishing port of Uusikaupunki. Marinated fillets are packed by hand in glass jars in Rymättylä`s traditional fishing harbour. The product has been awarded the Key Flag Symbol that that recognizes Finnishs manufacturing.