In Norway, the definitive Christmas dinner is eaten at Christmas eve, usually starting around five or six in the evening. As with most things related to Christmas, there are traditions to consider, and most people will have one of roughly five different traditional meals, and almost always the same thing each year. There are of course variations in the sides and so on, but I would guess that 90% of the population will have one of "pinnekjøtt", "svineribbe", turkey, fresh cod or "lutefisk". In order to make it to 24 articles, I'm going to write about each of these meals (except turkey), and as requested by Ulf, the topic for today is "lutefisk". But first, the legal stuff:
I have eaten lutefisk two or three times. The first one or two was years and years ago, and the last time was years ago. Hence, I don't have a lot of personal recent experience, and this article will partially be based on prejudice. However, lutefisk is of course chemistry, so in addition to experience and prejudice, there is also fact. I will try to keep all three separate.
"Lutefisk" means "lye fish". In other words "sodium hydroxide fish". To make lutefisk you start with dried cod (or I suppose you start with cod, and then dry it, but dried cod is commonly available, and using it shaves about six months off the cooking time for lutefisk, so that's what most people do), which you soak in water (makes those six months seem like a waste) for some days. You then replace the water with a solution of lye, leaving the fish in for another few days. At this point, the fish is highly alkaline, so before you can eat it, you soak it in water for a few more days. After the second soaking, the fish is cooked, and then eaten.
During this process, the lye will break down a lot of the proteins in the fish, giving the "desired" jelly-like quality. A lot of people believe that the lye will also turn the fat in the fish into soap (as did I, until quite recently), as mixing fat and lye is the traditional way to make soap. However, this process also requires heat to produce soap in significant amounts, and the tiny amount of soap which is formed is probably removed by the second round of soaking in clean water.
Unsurprisingly, considering it has been left in lye for days in order to break down any interesting compounds, lutefisk doesn't taste very much. It tastes mostly like fish, only less so, and has a somewhat dodgier consistency. So not particularly good, and not particularly bad either.
As dried cod has been a common foodstuff in Norway for centuries, and as lye has been commonly used for cleaning for centuries, it's not hard to imagine that at some point, someone dropped a piece of dried cod in a bucket of lye. It is then only slightly less plausible that they didn't discover it until a few days later, and furthermore that they were poor people who couldn't afford to throw away a large piece of dried cod just because it looked a bit like a jellyfish, so they soaked it in water and ate it. I would say, however, that even in the current economic situation, there is no reason to keep up this practice, and certainly no reason to purposefully put excellent fish in lye.
When you hear people talking about lutefisk, it is quite common that they don't actually talk that much about the fish itself, but about what they serve it with. Common sides with lutefisk include potatoes, mashed peas, mustard, bacon, butter, grated brown cheese, stued swedes, carrots, flat bread and "lefse", in addition of course to salt and pepper, and beer and aquavit. Most people use only a selection of these, but the point is that the sides usually get more attention than the lutefisk itself, the reason being that the lutefisk itself doesn't taste very much.
Even though one would assume lutefisk would be something found only in Norway, it is actually popular in parts of the US with a Norwegian heritage. I find this a bit weird, as I would have thought getting rich and not having to eat spoilt fish would be one of their ancestor's motivations for going to America in the first place.