A whole fish hot off the grill—with its tempting crisp skin and juicy, tender meat—is one of my favorite foods, both to cook and to eat. I like to grill fish whole because, with the skin and head intact, they look so dramatic, and the skin keeps the fish moist and seals in the flavor. Yet because fish is more fragile than beef or poultry, it requires a little extra attention to keep it from falling apart on the grill. Choosing the right type of fish and cooking it over a fire that’s not too hot helps to keep the fish moist and flavorful—and in one piece.
Pick a firm fish for grilling
Firm-fleshed fish with a high oil content are the best choices. A high oil content helps keep the meat moist and gives you a bit of an advantage in getting the fish off the grill in one piece. Try strong-flavored fish, such as salmon, mackerel, and bluefish; they’re particularly complemented by the distinctive, smoky flavor that grilling gives them. Less oily fish—snapper and rockfish, for example—can be grilled, too. To keep their flesh moist and prevent sticking, brush them with oil before you put them on the grill.
Shop for fish with your eyes and nose. When choosing fish for grilling, the general rules of freshness apply: Put your nose near the fish; it should smell fresh, not strong or unpleasant. The eyes should be bright and full, not murky or sunken, and the flesh should feel firm and bounce back when pressed. Fresh fish is bright and shiny, not blemished or slimy.
When buying fish to grill, have your fishmonger clean and scale it. Some cooks say that grilling a whole fish with the scales intact will make the fish less likely to stick to the grill, but I find it just makes a mess. A large fish like a salmon will be easier to serve if you have it boned before you cook it. The same is true for mackerel, too, but because of its anatomy, don’t expect to get out every last bone.
Add more flavor to fish with stuffings and marinades
Another advantage of grilling a whole fish is that you can fill the cavity with fresh herbs or slices of lemon, or you can brush the insides with mustard or other seasonings. Once the cavity is filled, tie the fish with several pieces of butcher’s twine to keep the filling inside. (I don’t bother tying up small fish like mackerel.) Tying the fish also makes it easier to handle because the belly won’t flop open as you try to turn it.
Marinades are another great way to flavor grilled fish. Just don’t leave fish in an acidic marinade for more than a few hours. Acids such as lemon juice and vinegar will “cook” the flesh and, if left too long, can give the fish an unpleasantly mushy texture.
When using a glaze, baste only the inside of the fish before grilling; brush the outside with the remaining glaze once the fish is off the grill. Glazes usually contain honey or sugar, which, if basted on the skin before grilling, can cause the fish to stick and burn and generally make a mess of the grill.
Use a clean, hot grill to keep fish from sticking
You should always grill on a clean rack, but this is especially important when cooking fish. Food will stick to a dirty grill, and if your fish sticks, your dinner is doomed. Also, be sure the grill is hot before you put the fish on it. If the rack and fish heat up together, they’ll form a bond that can be tough to break.
Once the grill is hot, give it a good scraping with a grill brush to get rid of any residue. Then, season the grill with a bit of oil for extra protection against sticking. I use a tightly rolled terry-cloth towel tied with twine and soaked in oil and rub it quickly over the grate. Just don’t use too much oil or it will drip into the fire and cause flare-ups.
Grill fish over a gentle fire
Because fish is delicate, it doesn’t require the intense heat that’s needed to sear meat and poultry. Set the grill rack at least four inches from the fire and grill the fish directly over moderately hot coals. If grilled over too high a heat, the skin will burn before the meat can cook.
Turning a whole fish is the most nerve-wracking part. For the best results, let the fish cook for several minutes before turning, and turn it only once. For a larger fish, use two spatulas or a two-pronged sauté fork and work carefully.
A fish tends to come off the grill easiest when it’s done. In other words, if you have to chisel at the underside when turning it because it’s sticking, it probably isn’t done on that side yet. Leave the fish on until it comes off the grill with only a moderate amount of encouragement.
Cooking times will vary depending on the fish you’re cooking and how hot your fire is. To test for doneness, slip a small knife into the back of the fish and gently pull the meat away. The meat should be moist and cling for a moment before coming away. Don’t cook the fish until it flakes or it will be dry.