Pickled herring, also known as bismarck herring, is a delicacy in Europe, and has become a part of Baltic, Nordic (Inlagd sill), Dutch, German (Bismarckhering), Czech (zavináč), Polish (śledzie w occie), Eastern Slavic, Scottish and Ashkenazi Jewish cuisine.
Most cured herring uses a two-step curing process. Initially, herring is cured with salt to extract water. The second stage involves removing the salt and adding flavorings, typically a vinegar, salt, sugar solution to which ingredients such as peppercorn, bay leaves and raw onions are added. In recent years, other flavors have also been added, due to foreign influences. However, the tradition is strong in Denmark, Sweden, Finland, Norway, The Netherlands, Iceland and Germany. Onion, sherry, mustard and dill are some of the traditional flavourings.
Pickled herrings have been a staple in Northern Europe since Medieval times, being a way to store and transport fish, especially necessary in meatless periods like Lent. The herrings would be prepared, then packed in barrels for storage or transportation.
In the Nordic countries, once the pickling process is finished and depending on which of the dozens of classic herring flavourings (mustard, onion, garlic, lingonberries etc.) are selected, it is eaten with dark rye bread, crisp bread, sour cream, or potatoes. This dish is common at Christmas, Easter and Midsummer, where it is frequently eaten with akvavit. Often, it is incorporated in a Fischbrötchen.
In the 19th century, people in Berlin developed a special treat known in English as soused herring or rollmops. Rollmops are pickled herring fillets rolled (hence the name) into a cylindrical shape around a piece of pickled gherkin or an onion. The word is borrowed from the German.
Pickled herring, especially brined herring, is common in Russia and Ukraine, where it is served cut into pieces and seasoned with sunflower oil and onions, or can be part of herring salads, such as dressed herring, which are usually prepared with vegetables and seasoned with mayonnaise dressing.
Brined herring is common in Ashkenazi Jewish cuisine, perhaps best known for vorschmack salad known in English simply as "chopped herring" and as schmaltz herring in Yiddish. In Israel it is commonly called as "dag maluach".
Pickled herring can also be found in the cuisine of Hokkaidō in Japan, where families traditionally preserved large quantities for winter.
In Nova Scotia, a province of Canada, pickled herring is called "solomun gundy" and is quite popular. Not to be confused with the Jamaican term for a pickled fish pâté.
Pickled herring is one of the best sources of natural vitamin D3. It is also an excellent source of selenium and vitamin B12. 100 grams may provide 680 IU of vitamin D or 170% of the DV, as well as 84% of the DV for selenium and 71% of the DV for vitamin B12. 
Pickled herring is one of the twelve dishes traditionally served at Christmas Eve in Poland, Lithuania, and Ukraine.
Herring is enjoyed as a special Shabbos food by Ashkenazi Jews worldwide. It is a staple at Kiddushes and social gatherings. Many kosher establishments have begun to formulate new fusion-style herring dishes such as Oneg-Shabbos herring and herring-lox combinations. Younger herring consumers look for new and interesting styles, besides the simple pickled herring with onions. Herring is typically served on crackers such as kichel or Tam Tams.
- Dictionary.com - Bismarck herring
- Erich Urban, Das Alphabet der Küche, Berlin 1929, Artikel Rollmops, S. 201
- Brown CS and Bryant SG (1988) "Monoamine oxidase inhibitors: safety and efficacy issues" Drug Intell Clin Pharm, 22(3):232–235.