A wet down bag on a cold granite slab is more than uncomfortable; it drops loft and stops holding warmth entirely. Standard home laundry detergents break down the natural oils on waterfowl feathers, while high-heat commercial dryers can melt ultralight nylon shells. Restoring loft requires a specific approach before packed dampness turns into persistent mildew.
Gentle Washing and Gear Soap
Never wash a down bag in a top-loading machine with a central agitator, as the plastic fins easily tear delicate internal baffles. Use a front-loading washer on a delicate cycle with specialized down cleaner rather than household detergent. Run an extra rinse cycle to clear out every trace of soap residue from the feather clusters.
Restoring Loft in the Dryer
Drying down takes several hours on the lowest heat setting available. Place three clean wool dryer balls in the drum to break up wet feather clumps as the bag tumbles. Check the bag every thirty minutes to unstick stubborn damp spots manually and ensure the shell material stays cool.
Proper Storage Between Trips
Once completely dry, store the bag uncompressed inside a breathable cotton sack or hang it vertically in a cool closet. Keeping down tightly stuffed inside a compression sack during off-seasons crushes the feather structure permanently over time. Give your sleeping bag space to breathe so it remains trail-tested for your next ridge line campsite.