From gas leak scare to gourmand's treasure: The pungent journey of Sweden's surströmming

One instance that garnered a lot of attention happened in Stockholm when the fire brigade and the police were called to a building due to suspicions of a gas leak on a staircase. However, the cause was traced back to a can of surströmming.

It's noteworthy that the birth of surströmming was somewhat an accident. In the 16th century, Swedes, who sold fish to the Finns, used to pack the fish into barrels and add salt for preservation. However, due to a shortage of salt, sometimes little to none was added. The fish still made it to Finland, but ended up being fermented. The Finns found this amusing and requested the same order the following year. Consequently, Swedes themselves started eating these "spoiled" herring.

Now, fermented herring is produced differently. Caught in April or May (before spawning), the fish are placed in barrels filled with brine. They remain there for up to two months, after which they're canned. The fermentation process continues in the can, producing gases that often give the containers a spherical shape. Surströmming is usually consumed after about a year, but some believe that the older the herring, the better it tastes.

Swedes prepare a special sandwich with the pickled herring. The ingredients include thin bread called tunnbröd, chopped onions, sliced boiled potatoes (or mashed), small pieces of herring and gräddfil, which is a thick, sour cream. Depending on the bread's texture - crispy or soft - the sandwich is either rolled up or eaten traditionally.

To accompany the sandwich, a glass of milk or beer or even a shot of vodka is recommended.

Source: theregister.com, Wikipedia