How Long to Grill Salmon in Tin Foil | Foil Packet Guide

Grill salmon in a foil packet over medium-high heat (about 400°F) for 10 to 18 minutes, depending on fillet thickness.

You’ve got the salmon, the foil, and the grill hot. The last thing you want is to pry open that packet too early and find raw fish — or wait too long and end up with dry, flaking disappointment. The timing feels like the one variable you can’t guess, and most recipes don’t agree on a single number.

The honest answer is that the time depends most on how thick your fillet is. A thin fillet around half an inch might cook in 10 minutes, while a thick center-cut piece could need 18. The target temperature — 145°F at the thickest part — gives you the clearest signal, whether you’re cooking a single portion or a whole side.

The Real Timing Range for Foil-Wrapped Salmon

Foil packets trap steam and heat, creating a mini oven on your grill. That insulation means the fish cooks gently and evenly, but it also means you can’t rely on visual cues through the foil. You need a time range and a thermometer.

Most recipe sources agree on a span of 10 to 18 minutes over medium-high heat. A standard 6-ounce fillet lands in the middle at about 14 minutes. Thinner fillets or those with vegetables take slightly less or more time, respectively.

Why Thickness Is the Main Variable

A fillet that’s one inch thick needs roughly 14 to 16 minutes. A half-inch fillet is closer to 10 minutes. Measure at the thickest point before you light the grill, and set your timer toward the lower end of that range — you can always cook longer, but you can’t un-dry salmon.

Why the Numbers Seem to Conflict

If you search for foil-grilled salmon timing, you’ll see 10 minutes, 16 minutes, and everything between. That range isn’t random. It reflects real-world differences in fillet thickness, grill temperature, packet size, and whether vegetables share the foil.

• Fillet thickness: A half-inch fillet from the tail end cooks faster than a one-inch center cut. Thickness is the single biggest factor in cook time.
• Grill heat consistency: Medium-high on a gas grill (around 400°F) is the standard, but charcoal grills vary more. An instant-read thermometer removes the guesswork.
• Packet size and contents: A packet with asparagus or zucchini holds more mass and takes longer — some recipes suggest 20 to 25 minutes for salmon with vegetables.
• Indirect vs. direct heat: Indirect heat gives a gentler cook and slightly longer times, often 12 to 18 minutes rather than 10 to 15.

The variation feels frustrating until you realize that a temperature reading at the thickest part is more reliable than any clock. Once you hit 145°F, the salmon is safe to eat, and the texture will be firm but moist.

The 14-to-18 Minute Standard for Average Fillets

For a typical 6-ounce fillet about three-quarters to one inch thick, the most commonly cited window is 14 to 18 minutes on a covered grill. Wellplated recommends this range in its grill foil packet 14-18 minutes guide, noting the salmon should be almost completely cooked through at the thickest part when you open the foil.

The key is to place the packet directly on the grates, lid closed, without flipping it. Opening the lid releases heat and extends cooking time, so keep it shut until the timer hits the lower end of your range.

If you’re cooking multiple packets, arrange them so they don’t overlap. Crowding the grill blocks airflow and creates uneven hot spots, which can leave one fillet overdone and another barely cooked.

How to Check Doneness Without Guessing

The most reliable method is an instant-read thermometer. Insert it through the foil or carefully open one end of the packet and test the thickest part of the fish. The USDA target of 145°F is the official safety threshold, though many cooks prefer the texture at 125 to 130°F for a moister result.

1. Set your timer on the low side: Start checking at 10 minutes for thin fillets, 14 minutes for standard cuts. Add time in 2-minute increments as needed.
2. Test the thickest part: Insert the thermometer into the center of the fillet, not near the edges, which cook faster. If you don’t have a thermometer, flake the thickest area with a fork — it should separate easily and have just a hint of translucency.
3. Account for carryover cooking: The internal temperature will rise about 5°F after you pull the packet off the grill. If you target 130°F on the thermometer, it will climb to about 135°F as it rests.

Many cooks find that opening the packet after the initial cook time and leaving it open for a minute or two lets excess steam escape. That helps the texture firm up slightly without drying out the fish.

Temperature and Doneness Levels to Know

The range between “perfectly cooked” and “overdone” is surprisingly narrow for salmon. Understanding your target texture helps you decide when to pull the packet off the grill. Per Theroastedroot’s cook 10 to 15 minutes guide, the cooked-through stage is when the fish is opaque and flakes easily — which typically happens around the 12-minute mark for average fillets.

Foil packets trap enough steam to cook the fish evenly, so you don’t need to flip them. The steam bath keeps the exterior from drying out while the interior comes up to temperature, which is why foil-grilled salmon tends to be more forgiving than grilling bare fillets.

A common mistake is overcooking because the packet stays sealed too long. Once the salmon reaches your target temp, slide the packet off the grill and let it rest for two to three minutes before opening — the residual steam finishes the cook gently.

If you prefer a more tender texture, aim for 125 to 130°F and pull the packet early. The carryover heat will edge the temperature up a few degrees as it rests. For food safety, the USDA recommends 145°F, though many home cooks find that target results in a drier texture if the fish isn’t oiled generously.

Thickness-Based Timing Quick Reference

Not every fillet is the same size, and guessing the time based on “looks about right” is a common source of overcooked fish. A simple guide based on thickness gives you a starting point that’s much closer to accurate than a single blanket recommendation.

These ranges assume the grill is preheated to medium-high with the lid closed during cooking. If you’re using a charcoal grill, temperature can fluctuate more than a gas grill, so checking with a thermometer at the lower end of the range is especially important.

The Bottom Line

Grilling salmon in a foil packet takes 10 to 18 minutes depending on thickness, with the most reliable check being an internal temperature of 125 to 145°F based on your preferred doneness. Start your timer on the lower side, test the thickest part with a thermometer, and let the carryover heat finish the cook while the packet rests off the grill.

Your next cookout deserves salmon that’s moist, flaky, and not a guessing game. Start with a fillet about three-quarters of an inch thick, preheat your gas grill to 400°F, and set that timer for 12 minutes before you reach for the thermometer.