The fermentation method carries on during the can – 'souring' as the Swedes refer to it – and ends in a bulging tin of fermented herring. Or rotten fish, as some (improperly) would say. Be aware: There aren’t several Surströmming get-togethers outside northern Sweden, but if you do locate just https://www.youtube.com/watch?v=OS365DWxnKQ