Dried salt cod, the main ingredient in the Brazilian bacalhoada described in the recipe Brazilian Salt Cod Stew, can be purchased in two forms: whole, bone-in, skin-on filets, which usually range from one to five pounds and can be found in Italian, Portuguese, and Caribbean groceries; and packaged boneless, skinless filets, which are typically pricier and more widely available in supermarkets. When shopping for whole filets of salt cod, look for whitish flesh with no spots or discoloration. The fish should smell mildly of the sea and be dry to the touch. Cooking with salt cod requires some advance preparation. If you're using boneless filets, place the fish in a bowl and rinse it under cold running water for 15 minutes, then soak it for 18 to 24 hours in the refrigerator, changing the water at least 3 times (longer soaking will yield a milder taste). If using whole, bone-in filets, rinse the fish for 15 minutes, then soak it for 36 to 48 hours in the refrigerator, changing the water at least 4 times. When using bone-in filets, purchase about twice the weight called for in your recipe to account for the skin and bones, which should be removed before you cook the cod. After soaking either kind, pinch off a piece of the fish and taste it; it should be pleasantly but not overpoweringly salty.