Down bedding should be washed only in a large-capacity front-loading washing machine. If you do not have one, use a machine at a laundromat. Some top-loading machines have large capacities, but the agitator in this type of machine can damage the bedding. Using the machine's gentle cycle, wash the bedding in warm water and mild non-bleach detergent. Run the bedding through the spin cycle a second time to remove as much moisture as possible.
Drying down bedding thoroughly is essential to prevent mildew growth. Using a large-capacity dryer, dry the bedding on a low heat setting; high heat can create hot spots and may burn the bedding. Add two or three clean tennis balls or white canvas sneakers to help speed the drying and to re-fluff the down clusters. It is likely to take a few hours to completely dry the bedding, so remove the item and shake every 20 to 30 minutes.
Though it is beneficial to clean down bedding, washing it too frequently can break down the clusters and remove the natural oils in the down and feathers. Wash down bedding only every three to five years if used throughout the year or once a year before storage during the off season.
You can extend the time between washing down bedding by protecting with covers. Top comforters with a duvet cover; these are available in colors and styles to coordinate with any decor. Zippered pillow protectors keep dirt, makeup and oils from soiling the down and can be used under a pillow case. Down mattress toppers can be covered with a thin mattress protector or pad. These covers can be washed more frequently and will protect your investment from everyday wear and tear.
Due to harsh chemicals used, dry cleaning down bedding is not recommended. If you do not wish to clean down bedding yourself or do not have access to large-capacity machines, take the items to a trusted professional cleaner who has experience cleaning them and will use water and gentle cleansers rather than chemicals.