If you have a white hat that seems to be ruined beyond repair, you can simply discard it or attempt to return it to its white state. There are varying methods for restoring a white hat or other clothing ranging from using bar soap immediately to bleaching. Care should always be taken when cleaning any item, and testing the cleaning solution in an inconspicuous place is an absolute must, according to author Linda Cobb.
Rinse the hat immediately if the accident has just occurred and not yet set-in. Thoroughly rinse the hat under hot water for five to 10 minutes if the spill was not protein or fat based like orange juice, fruit punch or wine. Rinse under cool water for 15 to 20 minutes if the spill contained a fat or protein such as blood, salad dressing or makeup.
Presoak the hat in 4-parts enzyme-based detergent combined with 1-part nonchlorine bleach in warm water for 30 to 45minutes in a bucket or sink. The enzymes will penetrate the stain and break it up, while the bleach will help to whiten the hat.
Combine 1 cup of salt and 2 cups of lemon juice in a bucket. Stir thoroughly until the salt dissolves. Gently ring out the presoaked hat and place it into the mixture, allowing it to absorb as much of the solution as possible. Air dry outside on a sunny day for six to eight hours. If raining, air dry in a laundry room or garage until completely dry.
Take the hat to a dry cleaner, if the above methods do not yield desired results. Ask the dry cleaner about possible options to return the white color to the hat.