Oskars Surströmming factory

Oskars Surströmming is Swedens most famous factory for this special product. Other factories make them too.

Surströmming (Swedish "soured (Baltic) herring") is a northern Swedish dish consisting of fermented Baltic herring. Surströmming is sold in cans, which may bulge after prolonged 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.

A Japanese study has shown that the smell of a newly opened can of surströmming is the most putrid smell of food in the world, beating similar fermented fish dishes such as the Korean Hongeohoe or Japanese Kusaya.