Anna’s Day, observed on December 9, is a Swedish name day that celebrates all people named Anna. It is sometimes referred to as Lutefisk Day because it marks the day to start preparing the lutefisk for the Christmas eve dinner in Sweden and some parts of Finland.

Lutefisk (lutfisk) is a traditional Nordic dish, mostly popular in Sweden, Norway, and parts of Finland. It is somewhat notorious for its specific odor. Some people find it terrible to the point of being disgusting, while others claim that lutefisk is the most delicious thing they’ve ever tasted. In any case, it leaves no one indifferent.

The preparation process of lutefisk was first described by Swedish writer, scholar and Catholic theologian Olaus Magnus in 1555. According to legend, Viking fishermen dried their cod on tall birch racks. During a neighboring Vikings attack, the racks were set on fire, but a rainstorm doused it. The remaining cod soaked in rainwater mixed with birch ash for months before some hungry Vikings discovered the fish, soaked it in clean water, and had a feast. They liked the taste and declared the lye-soaked cod a delicacy.

Today, the fish is treated with lye rather than birch ash, although ash is still used in Finland. Lutefisk is traditionally made from dried whitefish such as cod, haddock, pollock, ling, or burbot. The first step in the preparation of lutefisk is soaking the fish in cold water for several days, changing the water daily. The fish is then treated with a cold lye solution for two more days. After that, the lye-treated fish is soaked in cold water for another 4 to 6 days (with the water changed every day) to reduce its pH and make the lutefisk edible.

The lye breaks the bonds in some of the proteins contained in the fish, making its consistency very tender and jelly-like, as well as giving the dish its signature odor. However, it should be noted that the odor of lutefisk depends on the fish it’s prepared from. Lutefisk prepared from cod does have a very strong odor, while lutefisk prepared from haddock or pollock is almost odorless.

Lutefisk needs to be cooked before eating. It can be parboiled, steam cooked, baked, or microwaved. It is traditionally served with mashed green pees, boiled potatoes, small pieces of fried bacon, melted butter or white sauce, and other side dishes and condiments. When cooking and eating lutefisk, it is important to wash pans, plates, and utensils immediately because lutefisk left overnight is almost impossible to clean off.

Lutefisk is a traditional winter delicacy in some Nordic countries. There is a considerable increase in sales of lutefisk during the Christmas holiday season. Although very few Scandinavians serve it for their Christmas dinner these days, it is still considered part of the traditional Swedish Julbord and Norwegian Julebord (“Yule table”).

When people still prepared lutefisk themselves instead of simply buying it, they began the preparation process on Anna’s Day (December 9) for the dish to be ready for Christmas. Although home-prepared lutefisk is a rarity these days, some people still refer to Anna’s Day as Lutefisk Day and treat themselves on the occasion.