Fermented herring


Surströmming (fermented Baltic herring, or literally soured Baltic herring), is a dish from northern Sweden. Surströmming (Baltic herring) are smaller than the Atlantic herring which are fished off the west coast of Sweden in the North Sea.

The herring used for surströmming are caught just prior to spawning. The fermentation starts from a lactic acid enzyme in the spine of the fish. Pungent smelling acids are formed in the fish as well as hydrogen sulphide! Despite this many Swedes still love surströmming!

Fermented fish is not really so strange. The ancient Greeks and Romans made a famous sauce from fermented fish and Worcestershire Sauce also has a fermented fish ingredient.

It must be opened outdoors!

When opened, surströmming releases a strong and sometimes overwhelming odour so it must be eaten outside. Surströmming are normally eaten at the end of August but I've met Swedes who like to bury a can in snow and eat some at Christmas!

I also remember a case where a Swede in Gothenburg opened a tin in his apartment block which caused the whole apartment block to be evacuated because someone smelt the fish and thought there was a gas leak in the block. Indeed, according to a Japanese study, a newly opened can of surströmming has one of the most putrid food smells in the world! I don't know how they measured this, but I can easily believe the result.

Who likes it?

We carried out a poll to find out how many people like surströmming.  Out of 478 people who took part in the poll, only 31% said that they liked it, whilst 69% said that they hated it!

(32% of people who took part in the survey said that the smell was so bad that they refused to taste it!)

Opening a can of smelly fish provides an excuse for a party!

A surströmmingsskiva!

It took me ages before I could track down anyone who would admit to liking surströmming and most of them requested anonymity! But when I found an answer it was obvious: Swedes love an excuse for a party and opening a can of rotting fish provides an excuse. Really.

"Yes, ok it smells awful and doesn't taste very nice", the argument goes, "but we always have a good party when we open a can of surströmming!"

So if there is lots of snaps on offer it can be worth eating surströmming, according to some. I can think of better reasons for a party... 

How is it made?

The herring are caught in May, when they are in prime condition and just about to spawn. They are then put into a strong brine for about 20 hours which draws out the blood. The heads are then removed and they are gutted and put into a weaker brine solution. Canning starts at the beginning of July and goes on for about five weeks. The first cans go on sale on the third Thursday in August.

Storing the cans

The cans must be stored in a fridge. Fermentation continues in the can which causes the can to bulge noticeably.

Apparently, it is myth that cans will explode if not opened. There have been no know cases of surströmming cans exploding although they are not allowed on planes leaving the UK, but they are allowed on planes leaving from Sweden!

Eating surströmming

Surströmming is usually eaten in a sandwich (called surströmmingsklämma) made with tunnbröd (thin bread). The tunnbröd is normally buttered, but that is banned on my diet! The tunnbröd is then topped with:

  • sliced mandelpotatis (a type of potato grown in northern Sweden which is slightly sweet and waxy),
  • fillets of surströmming (sometimes they are cut up into small pieces),
  • finely diced red onion.

In southern Sweden, some crème fraîche or gräddfil (which is a bit like soured cream) is added along with chives, tomato and chopped dill.

Surströmming sandwiches are usually served with some Västerbottensost (a type of hard cheese), snaps and lager, although some people claim that milk is the best thing to drink with surströmming sandwiches.

If you get invited to surströmmingsskiva why not try it? You might like it!

John Duxbury


SwedishFood.com is run by a not-for-profit company set up to help English speakers around the world who would like to learn more about Swedish food. I am grateful to everyone who has helped with setting up the site, especially writers who have generously donated their time for free.

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