To find the warmest duvet, we need to determine the warmest duvet filling material.
In terms of heat retention and the ability to used as filling, these are the warmest fibers by weight:
- Qiviut [Musk Ox Wool]
- Yak Wool
- Alpaca Wool
- Camel Wool
- Sheep’s Wool
For more details, see my article explaining why these wools are ultrawarm.
After testing duvets filled with Yak, Alpaca and Merino wool, I’ve found that Yak wool is indeed the warmest.
All of these wools contain no lanolin so they are hypoallergenic and odorless. They have excellent moisture “wicking” properties. Body moisture is absorbed by the fiber, keeping sweat away to be released to the outside of the duvet.
This is the duvet I found to be the warmest:
Warmest Practical Choice
This duvet is very reasonably priced for an ultrawarm fiber like yak wool. However, it probably not the absolute warmest duvet on the market, that title goes to this qiviut-filled duvet:
Warmest Duvet Available
The Alpaca duvet I tried was also very warm:
Ave Maria 400 GSM Alpaca Wool Duvet/Comforter ($345 for King Size)
Camel wool also performs well as a duvet filling — for example see this duvet 100% Camel Hair Filled Duvet by Camel Comfort.