Every down bag comes with a care label and a set of manufacturer instructions, and those govern — this page describes what the process involves, not a temperature or a product to use. Shells, treatments and fills differ enough between bags that a general rule is the wrong tool.
Read the label first, and find the maker’s guidance
The care label carries symbols for washing, drying and what must not be done. Many makers also publish longer care instructions on their own site, and those go further than the label: they name the type of cleaner, say whether a hydrophobic treatment on the down needs particular handling, and state what will void a guarantee.
Two bags on the same shelf can carry different instructions. A shell with a durable water repellent finish, a hydrophobic down treatment, or a laminated panel each change what is appropriate. Where the label and something you read online disagree, the label wins.
Why washing is a last resort
Down works by lofting, and loft is what holds the dead air the bag’s stated comfort rating assumes. Anything that mats the clusters reduces it: body oils over time, and washing itself, which is mechanically hard on down and on the baffle stitching that keeps it in place.
So the sensible strategy is to need it rarely. A sleeping bag liner takes the oils and can be washed as ordinary laundry. Sleeping in clean base layers does the same job. Airing the bag after every trip, opened out rather than in its stuff sack, deals with moisture before it becomes a smell.
Wash when the loft is visibly reduced and airing has not restored it — that is the signal, rather than a number of nights.
What the process involves
The steps are consistent across most makers’ instructions, even where the details differ.
The bag is washed on its own, not with other laundry. Zips are closed and any drawcords loosened. Where a machine is used, makers commonly specify a large front-loading drum without a central agitator, because an agitator is what tears baffles. A hand wash in a bath is the alternative, and it is what some makers state for their own products.
Rinsing is repeated until the water runs clear, since residue left in the down is what makes it clump.
Then the part everyone underestimates: a wet down bag is heavy and the baffles will tear under their own weight if it is lifted by one end. It is supported along its length, or gathered and carried in a bundle, out of the machine and to wherever it dries.
Drying is where it goes wrong
Down comes out of a wash as compacted clumps, and drying is the process of breaking them up again. This takes far longer than people expect — makers commonly describe several cycles, and the bag is not finished until every clump has gone.
Whether a tumble dryer may be used, and at what setting, is stated on the label. Where one is permitted, the usual instruction is a low setting with clean dryer balls or something similar to knock the clusters apart, and the bag brought out and redistributed by hand between cycles.
A bag put away with damp down inside will not recover. That is the failure this whole process is really guarding against.
Storage afterwards
Store the bag uncompressed — a large cotton or mesh sack, or hung, rather than in the stuff sack it travels in. Compression is what tires down over months, and a bag stored loose keeps its loft for years longer than one left crammed in its bag between seasons.
Store it dry, somewhere that does not swing between damp and warm. And remember what the temperature figures on the label are: EN 13537 and ISO 23537 comfort and limit figures are laboratory values measured on a heated mannequin, quoted by the maker as an indication. A bag whose loft has been lost is no longer the bag those figures were measured on.
The manufacturer's own instructions come first, and this page does not stand in for them. Every weight, packed length, hydrostatic head, denier, micron rating, lumen figure and temperature on this page is reported from the manufacturer's own documentation, with its unit written as published, and named as such — none of it is measured here. A weight is reported as the maker counts it, and is never restated as another kind of weight, because the two are not the same figure.
What people ask before buying
Can I use ordinary laundry detergent?
Makers generally state a specific type of cleaner for down and say why, and some warn against ordinary detergents and against fabric conditioner. The care label and the maker's instructions are what govern here, not a general rule, because shells and treatments differ between bags.
How often should a down bag be washed?
Less often than most people assume. Washing is hard on down and on shell treatments, so the usual approach is to reduce the need for it — a liner, a base layer to sleep in, and airing the bag after every trip. Wash when loft is visibly down and airing has not brought it back.
Last reviewed 6 September 2026