The goal for perfectly cooked fish is a fillet that is tender, flaky, and moist. On the grill, the goal is the same but there’s an extra challenge: preventing the fish from sticking to the grate. Once you’ve mastered that skill, you’re well on your way to perfection. From The Total Grilling Manual: 264 Essentials for Cooking with Fire.
You’ll likely have the most luck with firm-fleshed fish such as tuna, swordfish, salmon, and halibut. As a general rule, count on about 8-10 minutes total for each 1-inch (2.5-cm) thickness of the fillet. Cutting fillets to an even size is a great way to make sure they cook evenly, and after cooking, let fish rest for 5 minutes or so to allow the juices to redistribute. Here are some of the best ways to make sure your fish makes it onto the grate and back again in one piece.
BRUSH & OIL Prepping the grill grate is always suggested; with tender fillets, it’s a must.
GREASE UP Lubricate the fish in addition to the grate. Mayonnaise is the unexpected and unrivaled condiment for the job. Brush fillets on all sides before grilling for best no-stick results.
BRING TO ROOM TEMP Remove fish from the fridge and let sit at room temperature 5–10 minutes before placing it on the grill.
HEAT THINGS UP A hot grate will sear the fillet when it’s placed on top. Don’t force it—the fish should loosen somewhat when it’s ready to be turned.
HANDLE WITH CARE Flip your fish only once. More than that and it may fall apart. Carefully shimmy a thin metal spatula under the fish to lift it from the grill.
KEEP THE SKIN ON Skin will help your fish hold together when it’s cooked and turned on the grill grate. If you prefer fish without the skin, simply remove it after cooking.
USE A BASKET Another good way to prevent your fish from falling apart on the grill is to use a fish basket. It will hold your fish, however delicate, perfectly in place.
GET A PLANK Grill whole fish or a large fillet on a plank (such as wood or pineapple) to keep it in one piece on the grill.