Holy Grail? 'Hydrophobic' Down Insulation by Sierra Designs

The company backs off just short of saying “waterproof.” But a new down-insulation treatment used in a line of to-be-released sleeping bags and jackets from Sierra Designs is being touted as “revolutionizing” the category.

Called DriDown, the magic water-resistant fluff is regular goose or duck down insulation covered in a secret polymer chemical of which the company gives no details. It is applied to “individual down plumes” that are touted to keep dry longer in the presence of water, be it rain, melting snow, or a down sleeping bag accidently dropped in a creek.

Though synthetic insulation like Primaloft has been widely embraced in the outdoors, down is still the gold standard for its warmth-to-weight ratio. But synthetic insulations trap heat when they get wet, whereas normal down clumps and flattens, killing its heat-trapping power and making it all but useless.

Sierra Designs hopes to change the equation with the new sleeping bags and down jackets, including men’s and women’s jacket models. The sleeping bag line includes the likes of the Zissou 0 HI model, which will weigh about 3 pounds and cost $299 when it comes to market in June. It is a zero-degree winter bag with 600-fill down.

The company says DriDown resists water to a large extant, but it is not waterproof if submerged or soaked. If it does get wet, Sierra Designs said it will dry much faster than old-fashioned, untreated feathers.

In total, there will be five sleeping bags in the line and at least four jackets. The bags will use a 600-fill down that’s treated with the magic polymer stuff. In June, the line will debut at REI stores and on REI.com, the “first-to-market” partner for the launch.

Here at GearJunkie we’re longtime fans of down, though we always resort to synthetic insulation if the trip might be wet. With the DriDown line, maybe this will be less of a concern. We can’t wait to zip one of the bags up and go to bed for a test outdoors, no matter what state of moist, wet or dry our bag is in after a long day in the outdoors.

—Stephen Regenold is founder and editor of www.gearjunkie.com.