Empty the water from the kettle when it’s done being used and set it upside down on a towel to drain and dry before storing it. Avoid leaving water in it in between uses.
Wash the kettle with warm soapy water. Use a soft-bristled brush to get into places your hands cannot. Rinse it out well and place it upside down on a towel to air dry with the lid off.
Remove rust from the cast iron kettle humidifier with a fine piece of sandpaper. Rinse the area off under running water and pat it dry with a soft towel. The kettle will need to be re-seasoned after removing the rust.
Re-season the cast iron kettle humidifier by wiping the outside with food grade cooking oil. Pour a cup of cooking oil into the humidifier and close the lid before swishing it around and pouring the oil out to coat the inside. Place the kettle into the oven at 400 degrees Fahrenheit for half an hour.
Store your cast iron kettle humidifier in a cool dry place with the lid off when it isn’t needed. Keep two to three paper towels inside to absorb any moisture from humidity that may accumulate inside.