Washing a whole sleeping bag is an involved and time consuming job, and if you have any doubt about carrying out the task yourself then you should have it professionally cleaned by a specialist down cleaning service. Furthermore if you do not have immediate access to a tumble dryer, please do not attempt to wash a down sleeping bag yourself. The following advice assumes access to a tumble dryer.
You should only wash your down bag occasionally - obvious signs of dirt or odour, usually accompanied by the bag failing to loft sufficiently are usually the signs that it is time to wash your bag.
As with down-filled clothing, provided you have an adequately sized washing machine, the difficult part is not actually the washing, but the drying. Most sleeping bags can be washed in a typical household washing machine and dried in a tumble dryer. Larger bags (with more than 1000g of filling) should only be washed in large domestic washing machines or be professionally cleaned. Alternatively you may choose to hand-wash your sleeping bag. Do not dry clean your down sleeping bag.
Your bag should ideally be washed using a specialist down cleaning product such as
Grangers Down Wash,
Nikwax Down Wash Direct,
Storm Down Wash, or
Fibertec Down Wash Eco. If these aren’t available then soap flakes which can be purchased from a supermarket are also fine. Do not use detergent or fabric softener.
Before you begin, if using a machine, clean any detergent out of your washer: if you use the powder drawer, give it a thorough clean, pouring hot water down it to remove any residue. Finally, run a short rinse cycle with the machine empty to clear any remaining detergent.
Ensure all drawcords under tension are released and velcro tabs fastened. The side zip should be undone fully and the zip head disengaged.
Read the care label. Despite the care label possibly suggesting your bag can only be hand-washed, provided you select the appropriate setting, it is ok to use a domestic washing machine.
Select a programme with a low to medium spin speed setting such as Delicates, Woollens or Handwash and with a temperature setting of 30°C. Rinse extremely thoroughly (at least twice).
If hand washing, fill a large tub with warm water. Add the appropriate cleaning product as for machine washing. Gently submerge the bag - due to the amount of air contained within the bag this may be difficult to start with, but persevere. This first stage can be made easier by initially leaving the bag inside its stuff-sack when placing in the water. Once saturated the bag will quickly submerge itself. Gently wash the bag, massaging between your hands until you are satisfied it is clean. Rinse extremely thoroughly.
When removing your bag from the machine or tub, do so carefully, the bag will be heavy and the extra weight of wet filling could damage internal stitching. Your bag may well look flat, empty and / or lumpy. At this stage don’t worry.