When to Cover Food with Foil in the Oven—and When to Uncover It

Foil creates a covered environment. Steam released by the food cannot escape; it stays inside the dish and keeps the food from drying out. The same steam also helps heat reach the food more evenly. The tradeoff is the crust: where there is steam, the surface stays wet, cannot get above 100°C / 212°F, and does not brown. So food cooks under foil, but it does not brown. Any recipe that needs these 2 results has to uncover the food at a certain point.

For long-cooking dishes, the sequence is straightforward. Dishes such as oven kebabs, stews, lamb shanks, and whole poultry are cooked covered for most of the cooking time; during that time, the meat becomes tender without drying out. Remove the foil for the final 20–30 minutes; raise the temperature slightly if needed so the surface can brown. After removing the foil, spoon a few spoonfuls of the dish’s own juices over the top for color and shine. The same approach works for vegetable casseroles and baked pasta. Since the oven door will be open briefly while you remove the foil, allow the oven temperature to recover.

You can also cover food partway through cooking. If the surface has reached the desired color but the inside is not cooked yet, loosely cover the top with foil. The foil blocks radiant heat so the surface does not darken further while the inside continues cooking. This is a common way to rescue thick loaves of bread, fruit pies, and thick cuts of meat. Do not press the foil tightly against the food; tent it over the top. Foil stuck to the surface can damage the crust and tear it when removed. It makes no difference whether the shiny or dull side faces up.

Some foods do not need covering. Cookies, cakes, crispy potatoes, pizza, and breaded foods need dry heat; foil prevents them from forming a crust. If the top of a cake is browning too soon, lower the oven rack or reduce the temperature instead of using foil. If you are using a covered casserole dish, foil is unnecessary because the lid does the same job. An oven bag also creates a covered environment. Do not open the bag; instead, cut open its top only during the final stage so the food can brown.

Keep 2 details in mind when using foil. First, prolonged contact with acidic foods such as tomatoes, lemons, and vinegar can give the foil a metallic taste; use a covered dish or parchment paper for these foods. Second, sealing foil tightly around the edges of a dish can trap steam pressure inside, so leave a small gap along one edge. When opening foil from the oven, lift it away from yourself so the rising steam does not hit your face. Use tongs or oven mitts to remove the foil.