The fermented skate dish traditionally eaten in Iceland on December 23 is skata.
More precisely, it is usually called kæst skata, meaning fermented skate. The custom is associated with Þorláksmessa, or Saint Thorlak’s Mass, a day honoring Þorlákur Þórhallsson, a medieval bishop and Iceland’s patron saint. The tradition began in Iceland’s Westfjords and later spread more widely.
Skate is a cartilaginous fish. During fermentation, compounds naturally present in its tissues break down and produce ammonia, giving the dish its famously powerful smell. It is commonly served with boiled potatoes and melted sheep fat or butter, and some diners pair it with Icelandic schnapps called Brennivín.
Skata is often confused with hákarl, another pungent Icelandic specialty. Hákarl is fermented shark, while skata is fermented skate. The dish is normally eaten before Christmas Eve, making it a distinctive part of Iceland’s holiday preparations rather than the main Christmas dinner.