As chef Malin Soderstrom opened the can, the trapped air escaped with a hiss and filled the balcony of her waterside restaurant with the pungent odour of Sweden's infamous delicacy, surstromming.

The various YouTube videos on the subject, almost all of them hailing from the U.S., ultimately depicted people in the throes of regurgitation, doubled over in gag-inducing torment as the camera ...