Surströmming ( "soured (Baltic) herring") is a northern Swedish dish consisting of fermented Baltic herring, just like Japanese Kusaya fermented fish such as the horse mackerel, the flying fish, or the sharks. Similar fish is made world wide. Surströmming is sold in cans, which often bulge during shipping and storage, due to the continued fermentation. When opened, the contents release a strong and sometimes overwhelming odor, which explains why the dish is often eaten outdoors.

Canning

The herring is caught in spring, when it is in prime condition and just about to spawn. The herring are fermented in barrels for one to two months, then tinned where the fermentation continues. Half a year to a year later, gases have built up sufficiently for the once cylindrical tins to bulge into a more rounded shape. These unusual containers of surströmming can be found in supermarkets all over Sweden. However, certain airlines have banned the tins on their flights, considering the pressurized containers to be potentially dangerous. Species of Haloanaerobium bacteria are responsible for the in-can ripening. These bacteria produce carbon dioxide and a number of compounds that account for the unique odor: pungent (propionic acid), rotten-egg (hydrogen sulfide), rancid-butter (butyric acid), and vinegary (acetic acid).

One proposed explanation of the origins of this method of preservation is that it began long ago, when brining food was quite expensive due to the cost of salt. When fermentation was used, just enough salt was required to keep the fish from rotting. The salt raises the osmotic pressure of the brine above the zone where bacteria responsible for rotting (decomposition of proteins) can prosper and prevents decomposition of fish proteins into oligopeptides and amino acids. Instead the osmotic conditions enable the Haloanaerobium bacteria to prosper and decompose the fish glycogen into organic acids, giving it the sour (acidic) properties.

Historically, other fatty fish like salmon and whitefish have been fermented not unlike surströmming, and the original gravlax has resembled surströmming.

Eating surströmming

Surströmming is often eaten with a kind of bread known as tunnbröd, literally "thin bread". This thin, either soft or crispy bread (not to be confused with crisp bread) comes in big square sheets.

The custom in The High Coast area where this tradition originates from is to make a sandwich, commonly known as a "surströmmingsklämma", using two pieces of the hard and crispy kind of tunnbröd with butter, boiled and sliced or mashed potatoes (often mandelpotatis or almond potatoes) and sliced fish in between and nothing more.

In the south part of Sweden it is customed to use a variety of condiments such as diced onion, gräddfil (fat fermented milk/sour cream) or crème fraîche, chives and sometimes even tomato and chopped dill.

The surströmming sandwich is usually served with snaps and light colored beers like pilsener or lager. Other drinks of choice are svagdricka (a swedish low alcohol dark malt beverage brewed since the middle ages, slightly similar to porter), water or cold milk. However, exactly what to drink or not to drink to surströmming is highly disputed among connoisseurs. Some claims that cold milk is the right and only choice while others refer to svagdricka as the most traditonal drink. Surströmming is usually served as the focus of a traditional festivity, a "surströmmingsskiva" (surströmming party).

Many people do not care for surströmming, and it is generally considered to be an acquired taste. Conversely, it is a food which is subject to strong passions (as is lutefisk), and occasionally people like the taste on first try.

Museum

On June 4th 2005, the first surströmming museum in the world was opened in Skeppsmalen, 30 km north of Örnsköldsvik, a town at the northern end of Höga Kusten ("The High Coast") in north Sweden.

Controversy

In April 2006, several major airlines (such as Air France and British Airways) banned the fish citing that the pressurized cans of fish are potentially explosive. The sale of the fish was subsequently discontinued in Stockholm's international airport. Those who produce the fish have called the airline's decision "culturally illiterate," claiming that it is a "myth that the tinned fish can explode."

See also

• Rakfisk
• Gravlax
• Hákarl

Footnotes

External links

• Kallax Surströmming - Kallax Surströmming is a well known producer
• Wedins - A Surströmming producer
• How to make surströmming at home
• Fiskevistet - Surströmming Museum in Skeppsmaln (in Swedish)
• Höga Kusten - The High Coast World Heritage Site
• surstromming in Korean version - A personal page showing the surströmming recipe in Korean version