I Learned How to Wash a Bulky Down Comforter Without Needing to Take It to a Dry Cleaner

"You'll need an extra-large capacity front-loading washer to avoid compressing or damaging the down. Home machines are usually too small, so grab the biggest washer at your local laundromat and place your comforter inside. Select the delicate or gentle cycle and add a small amount of mild or all-natural detergent. Less is more here - too much soap can strip natural oils from the down and affect its fluff. Run the comforter through two rinse cycles to ensure every bit of detergent is washed out."

"Transfer the comforter to an extra-large capacity dryer and dry it on low heat. This part may take a few hours, but slow drying helps protect the down and prevents mold or mildew from forming inside. Add tennis balls to fluff. Toss in a few tennis balls (or wool dryer balls) to help break up clumps and redistribute the down. Every so often, pause the cycle, take the comforter out, and give it a good shake to help it fluff evenly."

Use an extra-large capacity front-loading washer to avoid compressing or damaging the down. Select a delicate or gentle cycle and use a small amount of mild or all-natural detergent. Run two rinse cycles to remove all detergent so the filling does not become weighed down. Transfer the comforter to an extra-large dryer and dry on low heat for several hours to protect the down and prevent mold. Add tennis balls or wool dryer balls to break up clumps and periodically take the comforter out to shake and redistribute the filling. Check for clumps or damp spots before finishing.

Read at Apartment Therapy