DownWool® insulation filling

With the unique material mix of DownWool® we achieve the best insulation and a perfect, dry and pleasant climate with low weight.

  • DownWool® - the better down: Unlike conventional down, DownWool® retains its insulating properties even in high humidity of up to 90%. This means DownWool® offers superior thermal performance, even in cold, wet conditions.
  • Larger temperature range: DownWool® products have a wider temperature range where you feel comfortable. Wool balances out temperature fluctuations.
  • Drier sleeping and carrying climate: The blend of RDS-certified down and 30% wool from the Alps creates a dry, balanced sleeping environment in sleeping bags and a comfortable wearing environment in jackets. Wool effectively wicks away moisture and provides warmth even when damp.
  • Best sleep quality: Longer sleep, falling asleep faster and sleeping through the night is possible thanks to the wool content in the DownWool® insulation filling.

What is DownWool®?

The DownWool® insulation consists of 30% mulesing-free wool from the Alpine region and 70% RDS-certified down. Grüezi bag® has been using this filling in sleeping bags since 2017, and in clothing since 2021. DownWool® offers significant advantages over pure down:

While down is highly insulating, it is sensitive to moisture (sweat, condensation, humidity, etc.). Therefore, Grüezi bag® has naturally enhanced its functionality by combining it with wool. The combination is perfect: The 30% wool content absorbs moisture from the air and perspiration, keeping the down dry and retaining its insulating properties.

In DownWool® The two materials are blended in a perfect ratio. Through a technically complex, mechanical process without the use of chemicals, the down and wool are permanently bonded, making them washable. You can sometimes feel irregularly shaped bonds of wool and down with your fingers, which indicates that DownWool® is not fleece.

DownWool® is made in Germany and machine washable at 30°C. So you can rely on a durable and uncomplicated product looking forward.

DownWool® under the microscope: This section shows a 0,005 mm section. You can clearly see how the wool (brown fibers) is embedded in the down (white fibers).

Why does DownWool® work?

The DownWool® combination is patent pending and offers significant advantages over pure down or wool products:

  • Down is lightweight and packs down small, much lighter than wool, and provides excellent warmth. However, down only insulates as long as it's dry and fluffy.
  • However, when it becomes damp (due to condensation, sweating or humid air), the fine branches of the down collapse, the down clumps together and the insulating capacity decreases considerably.
  • Chemicals are often used to make down water-repellent. With DownWool®, the addition of wool eliminates the need for any down treatment. Wool can absorb up to 30% of its own weight in moisture. This naturally keeps the down drier and fluffier, thus preserving its insulating properties.
  • The wool fiber consists of many small tunnels with capillary action. This allows it to absorb and release more than 30% of its own weight in moisture. It thus ensures effective regulation of moisture and body temperature.
  • Wool absorbs moisture and releases it to the outside in a controlled manner. This regulation allows for a warming or cooling effect, creating a dry, comfortable body climate.
  • Even when wet, it retains its warming properties, something no other material can do.
  • Wool is antibacterial and odor-neutralizing.
  • The filling has been used in Grüezi bag® sleeping bags for years and has won many awards.

DownWool® and down in comparison

Property DownWool® Daune
Heat-to-weight ratio Very good – similar to down Excellent – ​​unbeatably light & warm
moisture behavior Significantly better – wool actively regulates moisture

Bad – clumps when wet, loses insulation
Temperature regulation Excellent – ​​compensates for temperature fluctuations well

Good, but rather “tight”, tends to overheat
Odor resistance Better – wool has an antibacterial effect

Worse – can absorb odors


DownWool® remains stable in moisture and even increases the loft

We had our Grüezi bag® DownWool® filling tested to determine how its volume behaves at different levels of humidity. The renowned testing institute "Hohenstein Laboratories GmbH & Co. KG" exposed DownWool® to a relative humidity of 50% to 90% at 23°C and measured the volume change.

The testing process

To determine the volume, the filling material was filled into a cylinder (39 cm diameter) and the height was measured at three different locations. The measurements were taken after 24 hours of conditioning at different humidities.

The first measurement was carried out in the specific standard climate (23 °C and 50 % relative humidity) and increased to 90 % humidity.

Download test report from the Hohenstein Institute (PDF)

The result is sensational:

While down loses volume as humidity increases and therefore no longer provides warmth, The volume of the DownWool® filling material increases as the humidity increases and DownWool® insulates even better!

Specifically: DownWool® increases its loft by up to 28,9% at humidity levels of up to 90%. And more loft means better insulation, even in high humidity. The reason lies in the properties of the wool fiber: Wool swells when it absorbs water, increasing its volume by up to 30%.

Filling volume DownWool®: Test result report no. 24.1121291, 16.07.2024, conducted by Hohenstein Laboratories GmbH & Co. KG

DownWool 2.0 from spring 2026

With DownWool 2.0, Grüezi bag offers an even more powerful, sustainable insulation solution for demanding outdoor adventures.

The further development of the proven DownWool® insulation brings significantly improved insulation performance with the same filling quantity and therefore the same weight.

The 3-season Subzero sleeping bag features DownWool 2.0, which improves the EN comfort temperature by an impressive 4°C, while maintaining the same weight and dimensions.

More loft, more warmth – completely natural

This is made possible by an optimized production process: the wool is given a down-like structure, which leads to increased loft – and thus to improved insulation.

In addition, all previous advantages of DownWool are retained:

  • excellent heat output even at high humidity,
  • pleasant, balanced sleeping environment,
  • no impregnation of the down necessary.

DownWool® is available in the following Grüezi bag® products:

DownWool® jackets

They are the first Jackets worldwide with DownWool® insulation: It creates a warm, dry, and comfortable body climate entirely without chemicals. DownWool® balances temperature fluctuations that occur between periods of exercise and rest, or when transitioning from indoors to outdoors. The jackets also boast a sophisticated cut that guarantees plenty of freedom of movement, wind- and water-repellent, recycled outer materials without PFC treatment, and extended sleeves and back.

DownWool® sleeping bags

Depending on the temperature range, wool is combined with down as insulation (“DownWool®”) or, for very cold temperature ranges, wool fleece is used in a down sleeping bag (“DownWool® Hybrid”).

The high-quality Grüezi bag® sleeping bags have received numerous awards for their climate and cut.

DownWool® or Silkwool jackets? When do we recommend which insulation in a jacket?

If you need an insulating jacket for outdoors or on the mountain, then a Grüezi bag® jacket with DownWool® or SilkWool filling is ideal. Because the natural material insulates even in high sweating and humidity conditions and offers a excellent wearing climate in a wider temperature rangethat makes you feel comfortable. Ideal when you're on the move!

  • The "Refreshful SilkWool Jacket" is a versatile all-season jacket with light insulation (made of 50% wool and 30% silk), ideal for very active activities.
  • For colder days, the DownWool® jacket with insulation made of 70% down and 30% wool is ideal because, unlike pure down, it also insulates in high levels of sweating and humidity, and the wool content ensures a better wearing climate.
    • The "Senseful DownWool Jacket" is a warming jacket for weight fetishists while trekking, biking, hiking, taking breaks up on the mountain, or for the city.
    • The "Lightful DownWool Jacket" is a versatile insulation jacket for cool autumn and spring days.
    • The "Faithful DownWool Jacket" is a warm insulation jacket – ideal for winter sports such as skiing and winter hiking, cold days on the bike, or leisurely strolls through town.

DownWool® or Alpine wool? When do we recommend which insulation in a sleeping bag?

  • The sleeping bags with DownWool® filling offer an optimal balance of insulation and weight. The down content (90/10 duck down with 650+ fill power) cuinIt provides excellent insulation and makes the sleeping bag lightweight. Thanks to its moisture-regulating properties, the wool ensures an optimal sleeping climate.
  • Sleeping bags with AlmWolle insulation are designed for temperatures well above zero. They particularly excel in high humidity, such as near rivers, lakes, or the sea. AlmWolle can absorb a great deal of moisture without losing its insulating properties. This is why you'll always have a warm, dry sleeping bag with AlmWolle.