Rakfisk is a traditional Norwegian food of freshwater fish – trout or char – that’s lightly salted and matured in brine at low temperature for several months, then eaten without cooking. It’s soft, pungent and strongly flavored, and it’s a winter speciality, especially in inland Norway. It’s typically served sliced on thin flatbread (lefse or flatbrød) with sour cream, red onion and boiled potatoes.
How Rakfisk Is Made
Producers gut and clean the fish, salt it mildly and let it mature in its own brine at around 3–7°C for 3–12 months (Axelsson et al., 2026). A study of six producers found salt levels between 3.8% and 7.2% and ripening temperatures from 3.5 to 7.5°C; the brine microbes were dominated by Psychrobacter and Lactobacillus, and each producer’s microbiota was fairly consistent from year to year (Bjerke et al., 2019). The fish’s own enzymes soften the flesh.
The Safety Facts
- Botulism. From 1975 to 1997, 21 cases of foodborne botulism were reported in Norway, and half-fermented fish was the major cause. In one case, home-prepared fish that had first been stored at 13°C contained type E botulinum toxin (Jensen et al., 1998). Egypt’s fesikh, salted whole and ungutted, has a much larger type E record.
- Listeria. Rakfisk is eaten raw, and the acids produced during its fermentation are too low to stop Listeria monocytogenes growing – temperature is the main control (Axelsson et al., 2020). One of the most severe listeriosis outbreaks in Norway in recent years was caused by contaminated rakfisk, and producers are now testing protective cultures, buffered vinegar and other measures (Axelsson et al., 2026).
Our advice: don’t make rakfisk at home. If you want to try it, buy it from an established producer, keep it cold, and follow the label. People who are pregnant, older, very young or immunocompromised should avoid it, as with other raw, ready-to-eat fish products that can carry Listeria.
How Rakfisk Is Served
- Thin slices or fillets on lefse or flatbrød.
- With sour cream (rømme), finely chopped red onion and boiled potatoes.
- Often as part of a winter gathering, with beer or aquavit.
Other Nordic fish ferments with similar cautions: Sweden’s surströmming and Iceland’s hákarl. For a fermented fish product that’s cooked into food, see fish sauce.