There is a lot of information on the web these days about which is the best pure down duvet to buy, well that would be ours obviously, we are trying to sell you one! There are lots of countries branding their down, like Canadian, Hungarian, Pyrenean, Ultimate and the list could go on and on, but are they any good? What are the real factors that separate the average down and the good down?
Does down from colder countries really influence the quality and insulation of the finest down? You would think so as the colder it is the better the insulation needs to be, right? There are reports that the down is fluffier and lighter so it is packed tighter together to ensure that the cold wind does not penetrate the skin however down also acts as a temperature regulator, so if it get too warm the down separates and releases trapped warm air.
The best indicator is the test of Fill Power where weights are dropped on a specific amount of down in a tube and the rebound effect gives you a very good idea of the loft and lightness of the down. Cleanliness is very important here as any impurities can make the down heavier and less likely to be effective at temperature regulation, as the down does not separate as easily when warmed by the body.
The higher the fill power rating the better the down is at doing its job, you will get a much lighter and warmer duvet per grams per square meter of filling than you would with a lesser fill power rated duvet. Higher fill power rated duvets will also have better internal baffle walls to ensure that the down is spread more efficiently and stays in place over the body while you sleep. So it really does not matter which brand of down you go for, Siberian, Canadian, Hungarian or Pyrenean, the fill power test is the one you should really be looking at to get the best quality down duvet. High fill power duvets really do last longer, are warmer and much lighter than standard duvets.
Down, like any insulating material, provides warmth by creating pockets, or layers, of air which protect against the cold. The thicker the layer of air, the better the insulation. We measure the quality of down in fill power, a measure of the loft, or fluffiness of a down product. The more fill power a down product has, the thicker the layer of air inside it. Thus, a higher fill power means better insulation. Higher quality down will have greater fill power, meaning less material is required to provide the same level of insulation.
We measure fill power in CUIN, or cubic inches per ounce. To calculate this value, down is washed and dried, then put into a device called a Lorch cylinder. Once inside, a set amount of pressure is applied to the down. At that point, the height of the down is measured and this number determines the down's fill power. The fill power of our duvets ranges from 600 CUIN to 800 CUIN for products with the highest quality down.