Surströmming has a reputation built on challenge videos, but in Sweden it is a late-summer meal with rules of its own. Here is when it is eaten, how Swedes serve it, how to open the can, whether you can fly with it, and who should go easy.
When you need this
- You are in Sweden in late August or September
- You have been invited to a surströmmingsskiva (surströmming party)
- You want to try it, or buy a can to take home
- You are packing for a flight with a can in your bag
- You are pregnant, breastfeeding, or feeding children, and wonder if it is safe
What surströmming is: fermented, not rotten
Surströmming (“sour herring”) is Baltic herring, strömming, preserved by fermentation. The fish is salted, left to ferment in open vats, and then canned, where it keeps fermenting in the tin. That is why the cans bulge. The fermentation produces strong-smelling acids and hydrogen sulfide, which is the smell. The fish is fermented, not rotten.
It is an old food. The word is recorded from 1732, and fermented fish (surfisk) from 1572. For centuries it was everyday food for poor households, above all along the Norrland coast. It became a delicacy only in the later 1900s. Today it is made by around nine salting houses between Kalix in the far north and northern Uppland, plus a number of small producers.
It is not everyday food any more. About half of all surströmming is eaten north of the Dalälven river and half south of it, mostly around Stockholm. More than half of the people who eat it do so only once a year.
The High Coast and Ulvön
The name most tied to surströmming is Ulvön, an island in the High Coast (Höga kusten). Its salting houses were the first to sell surströmming in consumer tins, around 1890, which made it possible to ship it all over Sweden. One salting house remains on the island today, and a heritage society, the Surströmming Academy, was founded there in 1999. For the region itself, see the High Coast.
Premiere day: the third Thursday in August
The year’s new surströmming goes on sale on the third Thursday in August, the surströmmingspremiär. In 2026 that was 20 August; in 2027 it falls on 19 August.
Many guides, Sweden’s own tourism board among them, call this the “official” premiere. It is a custom. The date was once fixed by the authorities so that only fully matured fish reached the shops. According to Sweden’s national inventory of living heritage, the third Thursday was set in 1940 and was statutory until 1988; other accounts put the end later, in the 1990s. Either way, no law sets the date today. Producers keep it by tradition.
| Period | What happened |
|---|---|
| 1572 | Fermented fish (surfisk) first recorded |
| 1732 | The word surströmming first recorded |
| Around 1890 | Ulvön salting houses sell it in tins |
| 1940–1988 | Third Thursday in August set as a statutory sales date (per the living-heritage inventory) |
| Today | Producers keep the date by custom |
Surströmming parties cluster from late August into early September. Student nations at the universities hold premieres too; for them it is also about northern roots.
How to eat surströmming
The classic serving, as the Institute for Language and Folklore (Isof) describes it:
- Thin flatbread (tunnbröd), hard or soft; the soft kind is rolled around the fish
- Almond potatoes (mandelpotatis), a potato variety served with it
- Finely chopped onion, often red onion
- Sour cream (gräddfil)
Rinse and gut the fish, lay it on buttered flatbread with slices of potato and onion, and roll it up. Some eat it on a plate instead, with potatoes, tomato and dill. The sides are not decoration; they tone the fish down.
Many drink snaps and beer with it; others choose light small beer (svagdricka) or milk. Anything stronger than 3.5% to take away is sold only at Systembolaget, from age 20. It closes at 15:00 on Saturdays and all day Sunday, so a weekend party needs early shopping — see Systembolaget opening hours. For the snaps itself, see snaps and aquavit. And if you drink, do not drive: Sweden’s limit is 0.2 per mille.
Opening the can: outdoors and cold
A bulging can is normal, not a sign it has gone off. But it is under pressure, and a warm can opened indoors can spray brine that smells for days. Open it outdoors, and chill it first.
Swedes disagree on the details:
| Method | Who recommends it |
|---|---|
| Open it in a basin of water, then wash and gut the fish | Visit Sweden |
| Chill it in the freezer for half an hour, angle the can, cover the opener with a napkin | A Swedish food magazine, which finds opening under water messy |
| Open it over a sink, so any overflow rinses away | The same magazine |
Whichever you choose, rinse the fish before serving. Boneless fillets are also sold, which saves you the gutting at the table.
Can you take surströmming on a plane?
Usually not. Transportstyrelsen, the Swedish Transport Agency, says surströmming is usually not allowed in either carry-on or checked baggage because of the risk of leakage and damage, and tells travelers to check with their airline. Do not pack a can without the airline’s written yes; it can be refused at the airport, and a leak can ruin your and other people’s luggage.
Carry-on has a second problem: food that mixes solids and liquid counts as a liquid at security, so a can in brine falls under the liquids rules anyway. And whether you may bring it into your home country is a question for that country’s customs, not Swedish aviation rules.
Dioxin: who should go easy
Baltic herring contains the environmental pollutants dioxin and PCB, which the body stores for life. Livsmedelsverket, the Swedish Food Agency, gives this advice for herring from the Baltic Sea and the Gulf of Bothnia, which is what surströmming is made from:
| Who | How often at most |
|---|---|
| Children and young people | 2–3 times a year |
| Anyone pregnant or breastfeeding | 2–3 times a year |
| Anyone who wants to become pregnant in the future | 2–3 times a year |
| Other adults | Once a week |
The reason is the next generation. Dioxin and PCB pass to a fetus through the placenta and to babies through breast milk, and high exposure early in life may affect thyroid hormones, tooth enamel and, later, sperm quality.
Why is it sold at all? Since 2002 Sweden has had an EU derogation that lets Baltic herring over 17 cm, and certain other Baltic fish, be sold in Sweden regardless of their dioxin and PCB levels. The condition is that Livsmedelsverket informs the public about the risks and its advice, and reports to the European Commission on how it keeps over-limit fish from being exported to other EU countries.
Most herring in Swedish supermarkets, such as pickled herring in jars, is not from the Baltic and has lower levels. Farmed fish are lower too. If it matters, check the catch area on the pack — Swedish food labels explains where to look.
Buying and trying surströmming
Cans go on sale in Swedish grocery stores from the premiere, whole or as fillets, and many traditional restaurants serve surströmming in season, especially in northern Sweden and on the High Coast. Prices vary by shop, size and producer.
Availability is less certain than it was. In 2024, after WWF’s seafood guide red-listed Baltic herring over heavy fishing, some supermarket chains limited or stopped surströmming sales. So check a few shops, or eat it where it is made.
Practical information
| Item | What to know |
|---|---|
| Premiere day | Third Thursday in August: 19 August 2027 |
| Status of the date | Custom kept by producers; not law |
| Serving | Tunnbröd, almond potatoes, onion, sour cream |
| Opening | Outdoors, chilled; in water or over a sink |
| Flying | Usually not allowed in any bag; ask your airline |
| Dioxin advice | Children, young people, anyone who may get pregnant: 2–3 times a year; other adults weekly |
| A can | Price varies by shop and producer |
| Snaps and strong beer | Systembolaget only, age 20; Saturday until 15:00, closed Sunday |
FAQ
When is surströmming premiere day?
The third Thursday in August: 20 August in 2026 and 19 August in 2027. That is when the year’s surströmming goes on sale. The date was once set by the authorities so only fully matured fish reached shops; Sweden’s living-heritage inventory says it was statutory from 1940 until 1988. Today producers keep the date by tradition, not law.
How do you eat surströmming?
Rinse and gut the fish, then eat it on thin Swedish flatbread (tunnbröd) with almond potatoes, finely chopped onion and sour cream. Some roll it all into a wrap; others eat it from a plate with potatoes, tomato and dill. Snaps and beer are usual, though small beer or milk are traditional too. Eating it plain from the can is the hardest way.
How do you open a can of surströmming?
Outdoors, and cold. The fish keeps fermenting in the tin, so the can bulges with pressure and can spray brine. Visit Sweden advises opening it in a basin of water; a Swedish food magazine suggests chilling it in the freezer for half an hour, angling the can and covering the opener with a napkin instead. Rinse the fish afterward.
Can I take surströmming on a plane?
Usually not. Transportstyrelsen, the Swedish Transport Agency, says surströmming is usually not allowed in carry-on or checked baggage because of the risk of leakage and damage, and tells travelers to check with their airline. In carry-on, a can in brine also counts as a liquid. Whether your home country lets it in is up to its customs.
Is surströmming safe to eat?
For most adults, yes, in moderation. Baltic herring contains dioxin and PCB, so Livsmedelsverket advises children, young people, and anyone pregnant, breastfeeding or hoping to become pregnant to eat it at most two to three times a year; other adults can eat it weekly. Sweden sells it under an EU derogation that requires this advice to be published.
Where can I try or buy surströmming in Sweden?
Cans are sold in Swedish grocery stores from the third Thursday in August, whole or as fillets, and many traditional restaurants serve it in season, especially in northern Sweden and on the High Coast. Since 2024 some supermarket chains have limited or stopped sales over concern for Baltic herring stocks, so availability varies by shop.
Related guides
- Kräftskiva: the Swedish crayfish party — August’s other great food party, and how to join one
- The High Coast — the coast where Ulvön and the salting houses are
- Swedish street food — tunnbröd again, rolled around sausage and mash
- Swedish food labels — how to read origin and catch area on a pack
- Systembolaget opening hours — buying the snaps before the weekend
Facts verified 2026-09-25. Sources: Isof, Levande kulturarv, Jordbruksverket (Smaka Sverige), Livsmedelsverket, Transportstyrelsen, Sveriges riksdag, Systembolaget, Visit Sweden and SVT — full register in this topic’s source file. Found something outdated? Tell us and we’ll fix it.