Grilling is a great technique for cooking fish. Sure, I am a grilling enthusiast but there's something tantalizing about the smoky aromas and flavors of grilled food that can't be beat. I try to cook outdoors on my grill as much as possible. When grilling fish, think in three categories; steaky fish, fillets, and whole fish. Each of these categories has their own set of guidelines you should follow.
These are fishes like swordfish, tuna and opah. They behave most like a chop or a steak on the grill. They usually have moderate to high fat content and are firm and dense. This makes them easy to handle on the grill, and they sear well. To prepare these types of fillets, season them with salt and pepper and grill them over direct heat to the desired doneness.
Not all fillets are suitable for the grill. Choose species that are firm fleshed and on the thicker side. Look for meaty options, like snapper, salmon, grouper, striped bass, bluefish, mahi mahi, halibut, and monkfish. Avoid more delicate fillets like flounder, hake, haddock and pollock. As long as the grill is clean, well oiled, and hot (see below) grilling fillets is easy. Pat the fillets dry and season them with salt and pepper. If you're cooking skin on fillets, start with the skin side down. This will give you perfectly crisped skin. Whether you are cooking fillets with or without skin, cook them 75 percent on one side. Flip the fillets over and let this short burst of heat finish the last 25 percent of the cooking time. A good rule of thumb is seven minutes of total cooking time (over high heat) per inch of fillet thickness. You can adjust this to the preferences and the type of fish you're cooking; for example, you might like salmon medium rare but monkfish cooked through.
There's a lot to love about cooking whole fish. It allows for a beautiful presentation and cooking fish on the bone keeps it extra moist and flavorful. You can cook any whole fish this way (even more delicate species)—as long they fit on the grill! Whole fish should be scaled and gutted, and I prefer to remove all fins before grilling. Stuffing the body cavity of whole fish with slices of citrus and sprigs of herbs is a nice additional touch that perfumes and flavors the fish from the inside. As with fillets, pat the fish dry and season it with salt and pepper just before cooking it. One of the most important tips for grilling a whole fish is to handle it as little as possible once it's on the grill. Hot, clean, oiled grill grates are key here, as is a two-zone fire. Place the fish over the hot side of the fire, near the far edge of the grate. The top of the fish (where the dorsal fin was) should align with the edge of the grate. Let the fish get a good hard sear (about two to three minutes) over high heat. Next, carefully use a metal spatula to check if the fish has released from the grate. If it hasn't, it needs a little more time on this side. Once the fish has released (is not sticking to the grate), gently roll the fish over towards the center of the grill. Allow the fish to sear on the other side for another two to three minutes. If you are grilling smaller fish, you're done!
Larger, thicker fish require more time to cook. If you are using a charcoal grill, you have an advantage here. Use two thick, dry towels to grab the handles on each side of the grate. Lift it up and turn it so the fish is now the cool side of the grill. If you are using a gas grill and can't rotate the grate, gently move the fish to the cool side of the fire. Cover the grill, with the lid vents open, for the remainder of the cooking time. You can test doneness visually by sticking a knife in the thickest part of the fish—the meat should be opaque. An instant-read thermometer inserted in the same place should read 135°F.
Guidelines for Grilling Fish
Grilling over hardwood charcoal is my preferred method but the following tips work for grilling fish on a gas grill, too. To start, clean the grill grates thoroughly with a grill brush. Oil the grates liberally with an oil soaked rag or paper towel. Do not use oil on the food you plan to cook, this creates flare- ups. Then, build two temperature zones on the grill. Build the actual fire on just half of the grill floor. This will allow you to maintain more control as you cook. You can now move what you're grilling to the cool side if you want to slow the cooking process down and/or impart additional smoky flavor. You can do the same thing on a gas grill by setting one burner to high heat and another to low.
Once you've lit the fire/gas, give the grill plenty of time to heat up: The grates over the hot side of the grill should be very hot before you place food on them. Tossing a handful of wood chips over the charcoal or gas fire will give the cooked foods extra depths of flavors. I like apple and cherry wood, but it's important to experiment to see what types of wood you like best.