Bacalao is a dried and salted cod, mostly known for its use in the cuisines of the Iberian Peninsula, but also widely used in other regions, like Norway, Iceland, and the Caribbean. Produced for hundreds of years in Europe, it became a product of trade between the Americas and the Old World, which is the reason it's a traditional ingredient in many cuisines. By salting it, the fish retains its nutrients and becomes more flavorful. Traditionally, bacalao would be dried in the sun, but commercial production dries it indoors.
To prepare bacalao for a recipe, you will have to soak the fish in fresh water to remove the excess salt used to preserve the flesh.
Once it's desalted, you need to cook it immediately, but be mindful that because it has been salted, the flesh is already "cooked." Lesser cooking times are crucial for great results; otherwise, you might overcook the flesh and serve dry fish. Use it in stews, poach it, bake it with tomatoes and olives, flake it for salads, or serve over rice, potatoes, or starchy yuca. Make fried balls of bacalao, battered fish, the famous and garlicky pil pil dish, or cook it with peppers and onions.
Bacalao isn't like anything you've ever tried. Its flavor isn't salty as you would expect, but in fact mild, yet still fishy, with a hint of sweetness to it. After hydrating it, its texture is plump and the fillets are firm. Once it is rehydrated, bacalao becomes delicate and tender. The salting, drying, and hydrating process also changes the texture of the flesh, making it less tender than raw cod or similar white fishes.