How to buy salt cod
When you happen upon a recipe that calls for salt cod, or bacalhau, first of all, thank your lucky stars. Then look for the quality salt cod, like the one pictured above, that hail from Norway. You should have no trouble finding in Portuguese, Italian, Greek, Spanish, and Latin markets. Select the thickest, firmest pieces possible (it’s sorta a special thing to be able to get your hands on a thick, stunning specimen). And it’ll make for the most gasp-inducing accolades from anyone who’s in your kitchen.
How long to soak the cod
First, rinse the salt cod well under running water to remove any surface salt. Then place the piece or pieces of cod in a large bowl or other, more oblong container and add enough cold water to cover by at least a couple inches. Stretch some plastic wrap over the bowl so it’s tightly covered (trust us, you’re going to want this to be airtight) and refrigerate, changing the water several times, until the fish is sufficiently desalted for you, anywhere from 12 to 48 hours, depending on the type and size of the fillet. Take a nibble now and again. If the cod seems too salty, change the water again and let it sit for a few more hours. Bear in mind: You can always add more salt to the recipe later, but you can’t take any more salt away once the cod has been incorporated into your recipe.
How to cook salt cod
Pour enough water–or, if you prefer, milk to temper a little of the fishiness–to submerge the cod in a saucepan and bring to a boil. Reduce the heat to low, add the soaked and drained cod, and simmer gently until it flakes easily when poked and prodded with a fork, 15 to 20 minutes, depending on the thickness of your fillets. Drain in a colander and let cool. Remove any bits of skin, bones, and spongy ends and then carry on with the recipe. (And if you’re tempted to try to substitute fresh cod, for the love of all things good, don’t do it. Salt cod is a marvelously unique ingredient that brings a complex and, curiously, almost sweet taste and incomparable texture to dishes.)