Aluminum foil can be safely used on the grill and is a common practice offering several benefits for cooking and cleanup. While the material is safe under typical grilling conditions, proper technique and considerations regarding food acidity are important for the best results.
Safety and Science: Addressing Common Concerns
A frequent concern is whether the foil will melt on the grill. Aluminum foil has a melting point of approximately 1,220°F (660°C), which is significantly higher than the surface temperatures of most home grills (typically 500°F to 700°F). Therefore, the foil will not melt or fuse to the grates during normal use. While the foil is not flammable, it can trap grease and marinades. If these pool and are exposed to direct flame, they can ignite. Proper handling and drainage are necessary to prevent this fire risk.
Aluminum leaching into food occurs when the foil is exposed to high heat and prolonged contact with certain ingredients. Highly acidic foods, such as tomatoes, citrus fruits, or vinegar-based marinades, accelerate this leaching because the acid corrodes the aluminum. While the body efficiently excretes small amounts of aluminum, cooking highly acidic or salty foods in foil at high temperatures increases the aluminum content of the meal. For healthy individuals, occasional use is not considered a major health risk, but it is prudent to avoid wrapping highly acidic foods in foil for extended cooking times.
Practical Uses: Foil Packets and Grill Lining
One popular application is creating sealed foil packets, which essentially turn the grill into a steamer or oven. This method benefits delicate foods like fish fillets, shrimp, or chopped vegetables that might otherwise stick to the grates or fall through. The tightly crimped foil traps moisture and steam, ensuring the food remains tender and preventing it from drying out. The sealed environment also locks in flavors from herbs, spices, and marinades, allowing them to infuse the food as it cooks.
Foil is also widely used for grill lining, serving two distinct purposes: protection and cleanup. Lining the grates prevents small items from slipping into the fire and provides a solid surface for foods requiring a flat cooking area. When placed beneath the grates, foil acts as a drip pan, catching grease and drippings that would otherwise cause flare-ups and make cleanup difficult. This barrier helps maintain a cleaner grill and reduces the formation of polycyclic aromatic hydrocarbons (PAHs) that occur when fat burns on hot coals or heating elements.
Techniques for Optimal Grilling
To ensure the foil performs effectively, it is recommended to use heavy-duty aluminum foil or double-layer standard foil. This added thickness provides greater structural integrity, preventing the foil from tearing when handled or when supporting heavier foods. A common question concerns the shiny versus the dull side of the foil, but the difference in heat reflection between the two sides is negligible in a grilling environment. The choice of which side faces the food will not impact the cooking process.
Prevent food from sticking to the foil by lightly coating the contact side with cooking oil or non-stick spray before adding ingredients. When lining grates for fatty foods, pierce small holes in the foil to allow excess grease to drain away. This drainage prevents fat from pooling and potentially causing a grease fire, while still protecting the grill from the bulk of the drippings. For foil packets, tightly crimp the foil to create a seal, but leave a small amount of headspace inside to allow steam to build and circulate, which facilitates the steaming process.