"The explosions lasted for six hours," the owner of the pickling works, Hans-Erik Englund, said. His stock of fish was due to go on sale this summer.
Englund was alerted to the fire late at night. Four people were fast asleep above the storage room when the fire broke out.
"We went in and screamed that they had to jump out," Englund said. Wallets, phones and keys were left behind in the dash to escape the exploding fish cans.
The cans of fermented fish, already expanded by the powerful fermentation gasses inside, were heated by the fire and turned into explosive items.
"Thank goodness none of the firemen were hit," Englund told Swedish Radio News, adding that one of the cans leapt right over an outhouse roof, another shot over the bay to the neighbour's house.
"It smells like someone's frying fermented herring. The fire fighters were surprised," said Englund.
The fire happened near the northern town of Enånger.
Surströmming, or fermented Baltic herring, is a staple of traditional Swedish cuisine. When the cans are opened, the contents release a strong odour, which is why the fish is usually enjoyed outdoors.