The kind of salt cod we associate with the Mediterranean is the heavily salted and sun-dried stockfish that hang like wooden boards outside food shops. These are cod prepared as they have been for a thousand years, to produce a basic protein source that keeps in the hottest weather without going off.
While dishes like Provençal brandade de morue and Portuguese bacalao use it to best advantage, one should not think salt cod is intrinsically superior to fresh. Indeed, it only existed at all because refrigeration and freezing did not. Traditional salted fish is therefore more to be judged for its preservative merits than on its culinary excellence. The limitations are known and should be understood.
However, salting purely to improve succulence, flavour and texture is a splendid technique to embrace enthusiastically at home. Fresh or frozen cod fillets are exposed to salt for between 2 and 24 hours and then the fish is soaked to remove excess salt before use. That something so easy can produce such extraordinary and beneficial changes is difficult to believe until you try it yourself. It does not really work with less than
Once salted it will keep for a week without deterioration in the refrigerator, but no longer. Home-dried cod needs a maximum of 30 minutes’ desalination under a dribble of cold running water before use.