It's that time of the year again: Rotten Shark

The season of "Þorri" (Thorri) or the forth winter month in the Icelandic calendar has arrived. This is the time of the year when in the olden days Icelanders had finished all the more tasty and good foods and it was time to break out the less appealing delicacies known as "Þorramatur". Nowadays the consumption of this horrible food is tied to Þorrablót (Thorrablot), the traditional Icelandic midwinter festival. The traditional method of preserving meat was to submerge it in fermented whey, giving it a sour taste (you get the idea). In addition, burned sheep heads and rotten shark play a big role.
Nathan Myhrwold, author of the Modernist Cuisine, formerly the Microsoft CTO and an avid photographer, can tell you more about how the rotten or fermented shark in Iceland is prepared: