Of all the fish to grill, salmon is among the easiest and has the potential to yield some of the best results—if you shop smart and prep both the fish and the grill properly. While many other fish tend to be flaky and delicate, salmon is more robust, with a fattiness that helps protect it from drying out during cooking. These instructions are for salmon fillets; if you want to know how to grill salmon steaks, you can read our step-by-step guide here.
How to Choose Salmon Fillets for Grilling
You can cook wild or farm-raised salmon on the grill, though farm-raised tends to be more consistently fatty, which can work in your favor when cooking over such dry heat. If you do try to grill wild salmon, you'll have a higher chance of success if you get thicker fillets as well as fattier ones. Size and fattiness depend on the species of wild salmon as well as the time of year it was caught, along with other factors, so you may not have a ton of control over what you get.
The reality, though, is that in either case, wild or farm-raised, the thicker the fillet, the better. More thickness simply buys you more time for the skin to crisp while the heat of the grill penetrates and cooks the fillet. Thinner pieces are more likely to cook through and be well-done by the time the skin has had a chance to crisp up, whether you want to serve salmon at that level of doneness or not.
When shopping, that means you should ask for center-cut fillets, which come from the thicker portion of the fillet, and not the tail end, which tapers off into a thinner, more irregularly shaped piece. Salmon can range tremendously in size, especially if you're dealing with wild ones, but the center-cut fillet on most farm-raised salmon will be about one-and-a-half to two inches thick, which is ideal. That's gives you plenty of room to brown and crisp the exterior while hitting a rare or medium cook in the center.
You should also, if at all possible, seek skin-on fillets. The skin acts as a natural insulator, protecting the flesh from overcooking in the intense, dry heat of the grill. This allows you to spend more of the overall cooking time on the skin side, crisping it to a potato-chip-level of crackling crunch without totally hammering the flesh just below it.
As for portion sizes, I recommend getting the fish pre-portioned into individual six- to eight-ounce pieces. Not only is it much easier to portion when raw—once cooked, it simply doesn't cut as cleanly into individual servings—but smaller fillets are easier to flip over than a large slab of fish.
How to Grill Salmon Fillets: Step by Step
Step 1: Prep Your Grill
Setting up your grill for salmon fillets follows the same basic best practices for grilling anything else. You want to preheat your grill and grill grate, clean the grate well with a grill brush, and finally oil the grate. A hot, clean, and oiled grill grate will be much less likely to severely stick to your fish than a dirty, cold one.
You'll want to mostly cook your salmon over higher heat—the time it takes to crisp the skin and quickly sear the fleshy side is often about as long as it takes to also get a good medium-rare internal doneness—but you'll want a cooler area available just in case you need to cook it a bit longer but the fillet seems in danger of burning. That means you need to set your grill up with a two-zone fire, which will allow you to position the fish over the hot coals, but still have the option to move it off to the side if it's browning too quickly.
Step 2: Prep the Salmon Fillets
While your grill is preheating, you can prep your fish. It's important to dry the salmon well on both sides using paper towels—minimizing surface moisture helps speed the searing process and reduces the chances of the salmon sticking to the grill.
To that end, I also like to lightly rub the fillets with a neutral oil like canola or vegetable oil after drying them. It's just one more bit of insurance against sticking.
Step 3: Grill the Salmon Skin Side Down
Salt slowly draws moisture out of proteins like fish and other meats, so I make sure to sprinkle it on the salmon just before placing it on the grill. After we've made sure to dry the surface of the fish well, the last thing we want to do is get it wet again before putting it on the grill.
When putting the salmon on the grill, be sure to lay it skin side down first. This is going the be the side where we do most of the cooking, since, as mentioned above, the skin insulates the flesh from the heat while having plenty of time to dry and crisp.
There's a good chance that the skin will stick at first, even with all the grill and fish prep we've done, but it should release pretty easily once it's ready. Exact cooking times are hard to give, since there are so many variables to account for (the heat of the coals and the distance of the grill grate above them being two major ones), but you're probably looking at about four minutes or so on the skin side.
Many people wonder about the white stuff that sometimes clots on the surface of the fish. That's fish protein called albumen, and it's a sign that the fish is being overcooked. It's almost impossible to totally avoid it on the grill due to the high dry heat, though, so don't get too upset if you see a little of it form on the surface. Just wipe it away and continue.
Step 4: Flip the Fish and Finish
When you think the salmon is ready to be flipped, proceed with caution. Fight the instinct to slide a thin metal spatula under it, which is almost guaranteed to tear the skin. Instead, slide the thin tines of a carving fork or the long prongs of culinary tweezers down between the grill grate so that they're below the fish. Then, lift gently so that you use more of a prying motion to detach the skin from the grate.
Once free, you can roll the fillets over, using a metal spatula to catch them on the other side and lower them down gently.
You only want to cook the fish on the fleshy side long enough to reach your desired internal temperature 110°F (43°C) in the very center for rare, 120°F (49°C) for medium-rare, or 130°F (54°C) for medium.
If you do run into a situation where your fish risks burning on the outside before it's reached its final internal temperature, move it to the cooler side of the grill to finish cooking.
When done, the skin should be crackling-crisp and blistered in spots, while the interior should still be moist and silky. Following these instructions, that won't be too hard at all.