The oven method
Preheat to 200 °C (390 °F). Place the fish skin side down in an ovenproof dish, in a single layer, with space between the pieces. Bake for 30 to 40 minutes without foil. The fish is ready when it just flakes under light pressure.
Salt it first — this is the step people skip
Salt the fish lightly 30 to 45 minutes before it goes in the oven, and keep it cold. The salt draws out excess moisture, and that is the single most effective thing you can do to get firm rather than gelatinous fish. Lutefisk holds a great deal of water, and water is what ruins texture.
Foil or no foil?
No foil gives firmer fish and a slightly roasted surface. Foil traps steam and gives a softer, milder result. Both are correct — it is a choice about texture. If you are cooking lutefisk for the first time, skip the foil. One note: never let aluminium foil touch the fish directly, since aluminium reacts with any lye residue.
Other methods
Poaching is the traditional method and gives the mildest result, but the fish is fragile and a few extra minutes will destroy it. Steaming is the gentlest of all. An air fryer at 180 °C for 15 to 20 minutes works well for one or two portions.
How much per person?
Allow 500 g (about 1.1 lb) of raw lutefisk per adult. Premium loin cuts with low water content need less — 375 to 450 g. If lutefisk is the only main course at a party, go up to 600–750 g.
Nicolai's rule: do not open the oven door early. Lutefisk needs steady heat, and every look costs you temperature you cannot get back quickly.
Read next
For the full meal, see the traditional lutefisk recipe — or start with what lutefisk is.
Lutefisk.no is a Norwegian reference site on lutefisk, published by the seafood company Fiskeruta and reviewed by chef Nicolai Radmer Nielsen. The rest of the site is in Norwegian.