Surströmming, is fermented Baltic Herring and apparently is a popular delicacy in Sweden. The practice of fermenting fish allegedly grew out of necessity when salt was scarce, though why salt would be scarce and expensive near the ocean is not explained.
Also not explained is why this medieval practice should have survived into the modern age and why health officials have not put a stop to this.
But devotees of this Swedish fermented fish will tell you that it is definitely “not rotten! To imply as such is almost criminal,” though to my mind it would be difficult to tell the difference.
Basically the fish is left in barrels for a year or more to rot (okay, ferment) in its own juices. It is then canned and sold throughout Sweden. Perhaps I can get the distribution rights for America?
When the can is opened, out pours a disgusting brown liquid and an overpowering smell that will likely send you puking to the bathroom. The fish is then placed between two slices of hard bread and eaten as is, without even gutting it or cooking it to kill some of the bacteria. This intrepid world traveller tried it and lived to tell about it. He claims that the taste is not as bad as the smell.