General care for sleeping bags
Every sleeping bag needs care, but it should only be washed when it‘s really necessary because any fill, no matter whether down or synthetic, will wear and the loft will decrease slightly.
Preventive Care
There are ways to avoid stains and dirt build-up. As for the inside, use a thin and lightweight cotton or silk inlet – it does not only provide hygienic function, it is also easily washable and increases the temperature inside the bag if needed. If there is odour inside the sleeping bag, try to vent it inside out or use an anti-odour spray. Spot cleaning the shell with a little bit of laundry detergent and water is best before washing the bag. This is especially true around the hood and collar where hair and skin oils tend to accumulate. By holding the shell or liner fabric away from the insulation, the area can be washed and rinsed without getting the fill wet.
However, if spots, grime and grease take over, washing the sleeping bag will be the only solution. Many people prefer to have their bag professionally laundered. But remember that dry cleaning is not appropriate, especially for down.
Washing your Down Sleeping Bag
Washing
The best way to wash a down sleeping bag is hand-washing. Due to its size, your bag should be washed in a bathtub. Use warm water (max. 30°C) and add a gentle, non-detergent soap, ideally one that is made for washing down-filled items. Immerse the bag and gently work the soap in, then let it soak for 10-15 minutes. Drain the water and press out the remaining water. Now rinse it with cold water to get all the soap out. Let it sit for a few minutes. Drain the tub and press out remaining water. You may have to repeat the process multiple times until all soap is rinsed out.
Some manufacturers allow their down sleeping bags to be machine-washed. Make sure you use a gentle wash cycle and cold water as well as soap made for machine-washing down-filled products.
Drying
Air-drying is the safest way to dry the sleeping bag after washing. Shake it regularly to spread the fill and help rebuild the loft. Never put the bag in direct sunlight. Air-drying takes a long time, so you can alternatively tumble dry the bag, but only at very low or no heat at all. Check periodically to make sure the shell and the insulation are not overheating, because they might melt. When the bag is nearly dry, add some tennis balls to break down fill clumps and to restore the loft.
Washing your Synthetic Sleeping Bag
Synthetic sleeping bags should be washed and dried the same way down bags are (see "Washing your Down Sleeping Bag"). The preferred and gentlest method is hand-washing, but you can also machine-wash it at gentle cycle at max. 40° and with a mild soap. Make sure all the soap is removed and try to remove as much water as possible before laying it out to air dry. Check the manufacturer’s care instructions whether machine drying is possible. If so, choose the gentlest drying program with low to no heat since synthetics can melt easily when too much heat is applied.