The bane of many cooks: burnt-on food that refuses to come off CorningWare bakeware. To avoid damage to your delicate dishes, avoid using harsh abrasives or cleansers. With a little patience, you will need a lot less elbow grease to remove the food burnt onto your CorningWare dishes.
Wait for the CorningWare dish to cool completely before cleaning.
Soak the dish in a combination of 2 tsp baking soda per quart of water for up to five minutes, recommends the Porcelain Enamel Institute.
Empty the water, and rub the burnt-on food with a nylon or plastic scrub brush, but never use steel wool or scouring powder.
Sprinkle baking soda directly on the burnt food if any remains after an initial scrubbing and rub again with a towel or nylon scrubbing pad.
Rinse the dish again. Spray the burnt-on food with ammonia in a spray bottle, and scrub again to remove the food.
Hand wash the CorningWare dish with soap and water to remove any residual ammonia or baking soda.