Do foil packets on a charcoal grill get any flavor from the smoke?

Yes, a foil packet on a charcoal grill picks up some smoke flavor, but only a little. A sealed packet keeps most smoke away from the food, so what happens inside is closer to steaming than to smoking, and the smoke that does reach the food comes through gaps and folds rather than through the foil.

That is the plain answer, and it follows from how a packet works. Foil is a barrier. Wrap a piece of fish or a pile of vegetables in it and set it over lit charcoal, and the heat drives moisture out of the food into the trapped air. The packet puffs, the food cooks in that moist air, and the smoke from the coals stays on the outside of the foil. Some smoke finds its way in when you open the packet, and a loose fold lets a little through, but the packet is not a smoking chamber.

What a foil packet actually does to food

A foil packet is a small closed oven. Heat passes through the foil to the food, moisture from the food fills the space, and the food cooks in hot, humid air. That is why vegetables come out soft and fish comes out moist. It is also why the surface of the food never dries, and a dry surface is what takes smoke. Smoke compounds settle on food best when the surface is tacky and the air around it is moving. A sealed packet gives neither.

Compare that with an open grill. The Best Kamado Grills for Low Smoking and High Searing guide lists cookers built to hold smoke around food for hours. The Char-Griller AKORN, one of its picks, publishes a cooking range of 200°F to 700°F and a 445 square inch cooking area, and the maker describes the insulated steel body as retaining heat and limiting airflow. A kamado like that surrounds food with smoke. A foil packet sits on top of the same coals and keeps the smoke outside.

The Weber Summit Kamado S6, another pick in that guide, publishes a 24 inch cooking area and a diffuser plate that the maker says helps maintain consistent low temperatures for smoking. Those are the conditions that put smoke on food: low, steady heat and open air around the meat. A packet removes the open air, which is the part that carries the smoke.

Where the little smoke flavor comes from

Smoke reaches packet food in three places. The first is the seam. A folded or crimped edge is not airtight, and a thin stream of smoke works through it over a long cook. The second is the moment you open the packet. Smoke that has built up around the foil rushes in, and the food surface catches some of it. The third is browning. If you open the packet near the end and let the food sit directly over the coals, the surface dries and takes smoke and char the way any grilled food does.

That last step is the one worth planning for. A packet cooked closed from start to finish tastes of the food and the seasoning, with a faint smoke note at most. A packet opened for the final few minutes, with the food spread out on the grate, gets a real grilled surface. The difference is not the foil. It is whether the food ever meets moving smoke and dry heat.

For cooks who want smoke without a packet, the Best Pellet Grills and Smoke Tubes for Backyard Cooks guide covers tools built for the job. The LIZZQ pellet smoker tube, one of its picks, is listed at 12 inches long and the maker states it can produce smoke for up to 5 hours. The maker also states it is designed to work in any grill, gas, electric or charcoal. A tube like that adds smoke around open food. It does nothing for food sealed in foil.

Why indoor grills show the same limit

The indoor grills in the Best Indoor Grills for High-Heat Searing guide make the point in reverse. They sear food on a hot plate with no smoke at all, and the makers sell them on that basis. The Ninja Sizzle, one pick, publishes a maximum heat of 500°F and describes a perforated mesh lid that the maker says helps control smoke in the kitchen. The Hamilton Beach indoor searing grill publishes a searing heat of 450°F and a temperature range from 200°F to 450°F.

Those grills produce browning and char marks without smoke, because browning is a heat effect, not a smoke effect. A foil packet on charcoal works the same way. The food browns where it touches hot surfaces and where the packet is open to dry heat, and the smoke is a separate thing that a closed packet mostly blocks. If you want the smoke, you have to give the smoke a way in.

The T-Fal OptiGrill XL, another pick in that guide, publishes 1800 watts and nine automatic cooking programs, and the maker describes inclined plates and a juice tray that it says facilitate removal of excess fat. None of that is smoke. It is heat and drainage. A packet on charcoal is heat and trapped moisture. Both cook food well. Neither one is a smoker unless the smoke can reach the surface.

How to get more smoke flavor from a packet cook

Leave the top of the packet partly open, or fold it into a tray with a loose lid, so smoke can drift across the food while the foil still catches drips. Put the packet over indirect heat with the lid on the grill, so the smoke has time to sit rather than blowing away. Add a handful of wood chips to the coals, or use a smoke tube, and let the packet cook in that smoke for most of its time.

Finish open. When the food is nearly done, tear the foil back and let the surface dry over direct heat for a few minutes. That step does more for smoke flavor than any amount of time spent sealed. The foil still earns its place: it holds small or delicate food together, it keeps drips off the coals, and it lets you move a whole portion at once.

Seasoning matters too. Salt and dry rubs draw moisture to the surface, and a tacky surface holds smoke. Food sealed wet in foil stays wet, and wet surfaces take very little smoke. Pat food dry, season it, and give it air. The packet is a tool for moisture and convenience, not a smoke chamber, and treating it that way gets you the flavor you were after.

The short version

A foil packet on a charcoal grill gets a faint smoke flavor at the seams and when you open it, and that is all. The foil blocks the smoke that would otherwise settle on the food, and the trapped moisture keeps the surface too wet to take much. Open the packet for the last few minutes, cook over smoke with the lid down, and the food will taste grilled rather than steamed.