Fermented and ripened fish products in the northern European countries

In northern Europe a number of fish products are prepared in such a way that biochemical and microbial action can take place. These are complex processes for which there are few available scientific studies. This article covers the origin, manufacturing, characteristics, and consumption of traditional fermented fish products, including surströmming from Sweden, rakfisk from Norway, hákarl from Iceland, and the barrel-salted herring that was commonly produced in most of northern Europe.