Baking Sheet Basics

A baking sheet or cookie sheet provides a large, flat surface for cooking. Baking sheets sometimes feature raised edges on all sides to prevent cooking juices from spilling into the oven. Tilapia does not render as much liquid as fattier fish such as salmon or tuna. However, using a baking sheet with a one-inch lip helps keep the baking process as clean and tidy as possible. Spray the baking sheet with cooking spray, grease it with olive oil or line it with parchment paper to keep the fish from sticking to the cooking surface.

Cooking Time

Tilapia fillets are thin, usually less than an inch in thickness. The fish is generally available fresh or frozen from your local fishmonger or supermarket in sizes ranging from 3 to 8 ounces. The small size and thickness of tilapia, combined with the flat, shallow surface of a baking sheet, equates to a relatively quick cooking time. Bake tilapia fillets at 425 degrees F for approximately 5 to 10 minutes per pound, or at 350 degrees for about 20 minutes per pound. Err on the side of caution and check the fish often to avoid overcooking. A perfectly cooked baked tilapia should flake with a fork, remain moist and appear opaque white in color. It's not necessary to flip the tilapia over during cooking.

Packet Cooking

Packet cooking is one technique for baking tilapia on a cookie sheet. Packet cooking allows you to infuse the fish with an abundance of flavor without the juices running out onto the baking sheet or into the oven. Place a tilapia fillet on a 12-by-18-inch piece of greased aluminum foil or parchment paper. Season the fish as desired with salt, pepper, herbs, marinades, or rubs. Add vegetables such as onions, carrots or squash on top of the tilapia if you wish. Fold the foil or paper into a sealed package and place on the baking sheet. Baking times will vary according to the size of the fish, as well as the other contents of the packet.

Safety Tips

Tilapia does not smell fishy when it's fresh. A fish smell can indicate spoilage; malodorous tilapia should be discarded. Tilapia fillets can be frozen for 4 months. The fish does not need to be thawed before baking, but you need to add several minutes to the cooking time if you plan to cook frozen fish. If you choose to thaw tilapia before baking, place the frozen fish in the refrigerator for 18 to 24 hours per pound, or submerge the frozen tilapia into a bowl of cold water.