How to Cook Fish

Heart Healthy and Delicious

Fillet of salmon with vegetable
Fillet of salmon. alle12/Vetta/Getty Images

Everyone knows that fish is good for you. The fats in fish, especially fatty fish like salmon, tuna, and mackerel, are thought to help prevent heart disease, and can even aid in preventing diseases like Alzheimer's and strokes. But it seems that many people are afraid of cooking fish at home. Americans eat only about 15 pounds of fish per person per year, but we eat twice as much fish in restaurants as at home.

Buying, storing, and cooking fish isn't difficult; it just requires a little knowledge. This article is about how to cook fish steaks and fillets.

Buying Fish

  • Smell it!
    Fresh fish should smell sweet: you should feel that you're standing at the ocean's edge. Any fishy or strong flavors means the fish is past its prime; do not buy it. I still have a vivid memory of shopping in a local supermarket, watching an elderly gentleman sniff each portion of raw fish offered to him by the butcher. The gentleman rejected almost every fish because it didn't smell fresh. You can be sure that the fish he chose was moist, delicate, and delicious.
  • Look at it!
    Whole fish should look as they were just pulled from the water; bright eyes and firm flesh are signs of freshness. Fish fillets or steaks should be firm and bright looking, with no brown spots or discoloration.
  • Freeze it!
    Fresh fish should be stored in your refrigerator for only a day or two; it's very perishable. Any longer than that, and wrap the fish well in freezer paper and freeze it. Unless you live near a coast with a reliable supply of freshly caught fish, most fish that you buy will be sold frozen. Keep it frozen until you're ready to cook it. Fish can be thawed in the refrigerator, or under cold running water, or in the microwave. Be sure to cook it as soon as it's thawed.

    Don wrote and reminded me of a great trick - thaw frozen fish in milk! Place the frozen fish in a bowl and cover with fresh milk, then cover and let sit in refrigerator overnight. The fish will have a wonderful fresh-caught taste. Discard the milk after the fish thaws.

  • What about bones?
    Many fish, including trout and salmon, have a double rib cage, so the fillets may have small pin bones. You can remove these by pressing the flesh with your fingers, and removing the bones using a tweezer. It's possible to buy fillets of these species without pin bones, but they are generally much more expensive.

    Fish Science

    Remember in our discussion about How to Cook Beef, we learned that beef is red because a cow's hard used muscles need lots of oxygen and therefore have a lot of myoglobin, the molecule that transports oxygen around the body. Fish have a much easier life. They don't need to fight gravity to stay upright, and can move long distances with just a flick of a tail. Therefore there isn't much myoglobin in fish, so it tends to be light colored and translucent.

    When fish cooks, the proteins denature or unwind, then reattach to each other, or coagulate. This process squeezes out water and the molecules shrink, pressing closer together. You can see this process happening as the fish becomes opaque. Light isn't able to pass through the coagulated proteins; fish is cooked when it is opaque.

    Because fish have very little connective tissue and fat, they are quite delicate when cooked. A reliable doneness test is to check if the fish 'flakes'. Insert a fork or knife gently into the thickest part of the fish and twist. The flesh should begin to separate along the natural lines.

    Don't Overcook!

    There's a delicate balance between perfectly cooked fish and overcooked fish. First of all, remember the principle of residual heat: a pan will hold heat when it's removed from the heat source, continuing to cook the food for several minutes.

    For best results, cook fish until it's almost done, then remove the pan from the oven, microwave, stovetop or grill and let it stand for a few minutes to finish cooking.

    Some fish, especially tuna and salmon, can be served medium rare. I myself do not enjoy fish cooked this way, and serve all of my fish well done, but the choice is up to you.

    To Marinate, or Not?

    Marinating fish adds flavor and moisture to the flesh, but any marinating should be very brief. If fish flesh sits in acidic ingredients for more than 30 minutes, the acid will begin to denature the delicate protein, and you'll have a mushy fish when it's cooked. Even richer flesh of salmon and tuna should only be marinated for about an hour.

    Marinades include oil (extra virgin olive oil provides the best flavor) and an acidic ingredient like chopped tomatoes, red wine vinegar, or lemon juice, along with seasonings including salt and pepper.

    Depending on your tastes, seasonings can range from chopped jalapeno peppers and crushed red pepper flakes to fresh thyme leaves and parsley.

    Go to the next page to learn about fish cooking methods.

    There are many common methods used to cook fish; the most popular are described below. There's one important point to make about cooking fish: leave it alone! When you place the fish in the pan or on the grill, let it cook undisturbed for 2-4 minutes before you touch it. The fish will develop a nice crust and will release perfectly when it's ready to turn.

    Grilled Fish

    The sturdier and fattier fish, including grouper, salmon, tuna, swordfish, and shark, grill beautifully.

    Make sure that your grill is very clean and oil it lightly before adding the fish. Then leave the fish alone! If the grill is properly preheated and prepared, the fish will develop a nice crust and will release when cooked. For more delicate fish fillets, using a grill basket will make grilling any type of fish much easier. Just be sure to remove the fish from the basket as quickly as possible so it doesn't stick. I like Nigella Lawson's method for cooking thinner fillets on the grill; she simply puts a sheet of heavy duty foil on the grill and cooks the fish on that. Don't cover the grill as the fish is cooking; the cover traps too much of the smoke and overseasons the flesh.

    Steamed Fish

    A bamboo steamer is a great investment if you like this method of cooking fish. To steam fish, place water or stock in a large saucepan and add seasoning ingredients; everything from lemons to ginger will work.

    Bring the liquid to a simmer, place the fish in the steamer(s) and place over the simmering water. Do not let the liquid boil; this will cook the fish too quickly and it could overcook in seconds.

    Microwaved Fish

    The microwave oven will cook fish very well as long as you follow a few rules. First, make sure that you rotate the fish halfway through the cooking time so the fish cooks evenly.

    If the fillets are of uneven thickness, fold the thinner parts under each other so the fish is about the same thickness throughout. And standing time is very important; let the dish stand on a flat surface according to the recipe so the food finishes cooking.

    Broiled Fish

    Broiled fish can be really delicious, especially if you season the fish well before cooking. Be sure to preheat the broiler before adding the fish. Make sure the fish is 4-6" away from the broiler and watch carefully. Thinner fillets (1/2") probably won't have to be turned over; thicker fillets (1") should be carefully turned halfway through cooking.

    Roasted Fish

    Baking at a high oven temperature really concentrates the flavors of fish and helps the sugars on the surface caramelize for superior flavor. Roasting is baking at temperatures above 400 degrees F. You can season the fish with just about anything you like before roasting.

    Poached Fish

    Fish is poached in a flavored liquid called a court bouillon. Just about any aromatic herb or vegetable can be used in the poaching liquid. There's one important rule for poaching: do not let the water boil! The liquid should be barely simmering. If the water boils the outside of the fish will overcook quickly.

    Crockpot Fish

    Most crockpot recipes call for adding the fish toward the end of cooking time. At high temperatures, 1" pieces of fish will cook in about half an hour. Be sure to carefully follow the recipe instructions when cooking fish in a crockpot or slow cooker.

    Baked Fish

    Baking is one of the easiest ways to cook fish. Just follow the recipe instructions for cooking, covering, and standing times.

    Sauteed Fish

    Using just a bit of olive oil and making sure to preheat the pan are the two tips for a perfectly sauteed piece of fish. Also remember to let the fish cook undisturbed for 2-3 minutes to develop a nice crust. Be sure not to crowd the fish; cook it in batches rather than overcrowd the pan. The best way to saute thin fillets is to cook over medium high heat for 2-3 minutes, then turn, cook for another minute or two, then remove the pan from heat and let the residual heat cook the fish.

    Cook thick fillets 5-6 minutes on the first side, then reduce heat to medium and cook for 4-5 minutes longer.

    Fried Fish

    Deep fried fish is usually battered, then gently lowered into 375 degree oil and cooked for about 4 minutes per side, turning once and carefully.

    En Papillote

    Cooking fish encased in parchment paper or foil is a wonderful way to get the best results. The paper or foil holds in the moisture, concentrates the flavor, and protects the delicate flesh. Follow the folding and cooking instructions carefully. The packets can be cooked in the oven or on the grill.

    Go to the next page to get the wonderful recipes!

    Fish generally take 10 minutes to cook per inch of thickness. Just to be sure it won't overcook, start checking the fish at 7-8 minutes. Steaming is the one method where this rule doesn't apply; if you steam your fish, check for doneness starting at about 7 minutes. With all the knowledge and cooking skills you've learned, these will be the best fish recipes you've ever tasted.

    Best Fish Recipes

    • Microwave Salmon with Orange Sauce
      This super easy microwave recipe uses butter, nutmeg, and orange juice to make a flavorful sauce for moist and tender salmon.
    • Crockpot Salmon with Caramelized Onions and Carrots
      The crockpot may seem like a strange way to cook salmon, but this recipe is simply superb. The low, moist, and slow heat is perfect to cook salmon that is tender, moist, and so flavorful.
    • Toasted Fish and Bacon Sandwiches
      Even fish haters will love this recipe, with bacon and rich mustard accenting the perfectly cooked fish.
    • Honey Orange Fish Fillets
      A simple glaze of honey, orange juice, and dill glazes tender fish to perfection.
    • Lemon Salmon Pasta
      Lemon, leeks, bell peppers, and dill weed flavor the sauce in this easy one dish meal.
    • Grilled Mahi Mahi with Vegetable Slaw
      Your dual sided indoor grill cooks the fish to perfection in this mostly make-ahead recipe. You can also double the cooking time and cook the fish on an ordinary charcoal or gas grill.
    • Grilled Dilled Salmon
      This super simple four ingredient recipe can be made with just about any fresh herb you'd like. The lemon adds wonderful flavor and tenderizes the flesh of the salmon.
    • Spinach Rice Fish Rollups
      This delicious recipe, using spinach, rice, and cheese to stuff thin fillets, cooks to perfection in your microwave oven.
    • Tuna Artichoke Kabobs
      You could substitute swordfish or halibut for the tuna in this delicious and unusual recipe.
    • Red Snapper Veracruz
      Onion, salsa, tomatoes, and olives add flavor to this healthy and hearty fish entree.
    • Orange Roughy with Red Peppers
      This simple four ingredient recipe is full of flavor and is so easy! Use any color of bell peppers you like.
    • Curried Fish Fillets
      Fish is coated with lemon juice and curry, then cooked in the microwave. This beautiful dish is finished with a chutney grape sauce. Yum.
    • Veggie Fish Skillet
      Halibut fillets are perfectly seasoned with dill, lemon, onion, and tomatoes in this easy skillet recipe.
    • Oven Fried Fish Fillets
      The bread crumb coating makes a crisp crust on these easy baked fillets.
    • Salmon Fillet with Avocado Sauce
      This beautiful and colorful recipe is very delicious; the broiler cooks the fish to perfection.
    • Grilled Fish with California Sauce
      Tomato, avocado, and a vinaigrette salad dressing are the secret ingredients in this simple five ingredient recipe.
    • Crockpot Fish Chowder
      This healthy and delicious recipe is packed full of vegetables. The fish stays very tender when cooked in the moist heat of a crockpot.
    • Tangy Glazed Fish Fillets
      Horseradish, mustard, and lemon juice season thin fish fillets in this super easy recipe.
    • Roasted Salmon Fillets
      This very easy recipe concentrates the flavors of salmon and the seasonings into a perfect presentation.
    • Mustard Grilled Salmon Salad
      This delicious and easy recipe is perfect for company in the summer or fall.
    • Fish Fillets with Mushroom Sauce
      This easy baked dish uses fillets bathed in a creamy mushroom sauce to add flavor and moisture.
    • Grilled Swordfish with Tomato Salsa
      Tuna or salmon steaks can be substituted for the swordfish in this easy and fresh recipe.
    • Tomato and Cheese Fillets
      Another microwave recipe! You can use your favorite flavor of cheese in this simple recipe.
    • Poached Salmon Fillets
      Poaching is the most delicate method of cooking; the fish stays so moist and tender, with wonderful flavors.
    • Orange Roughy en Papillote
      This beautiful recipe is wonderful for entertaining. A white sauce seasoned with thyme, bell pepper, and mushrooms seasons the fillets to perfection.