In six days on backcountry skis and with material sleds across the largest plateau in Europe. Once through the cold chamber of the continent: the Hardangervidda in Norway! A treeless desert of snow, rock, and ice that stretches nearly 100 kilometers in all directions, with winter temperatures as low as -30°C, winter storms, and changeable weather. An absolute challenge for man and material, which, in addition to good preparation, above all requires high-quality expedition equipment. I can now tell you in detail how the Grüezi Bag Biopod Down Hybrid Ice Extreme – I was with the model with the final designation 190 W, i.e. the wide variant with a comfort cut – fared in the arctic climate of the Hardangervidda.

The Hardangervidda in Norway: the largest plateau in Europe and a desert of snow and ice in winter

GENERAL DATA

An extra wide sleeping bag for winter mountain and trekking tours. Comfortably cut, light and small in pack size. An elaborate hybrid construction made from the finest goose down (90/10, 800+ cuin, RDS certified) with an additional layer of alpine wool for the best insulation and a dry sleeping environment. A comfort temperature range of -8°C, a limit temperature of -15°C and an extreme temperature of -37°C.

So far so good. The product data sheet of the Grüezi Bag sounds extremely promising. What particularly interested me were the incredible number of additional features that the Grüezi Bag should have: a carbon heating element for the foot area, an adjustable hood with a so-called face baffle for a perfect fit, a 3D thermal collar, a two-way autolock zip with an insulating cover, a zip retaining strap and anti-snag zip to prevent pinching, anti-slip nubs on the underside of the sleeper and and and...

Many of these features should, on paper, solve problems that I had always struggled with with my previous sleeping bags. Could this be true? If so, then the Grüezi Bag had to be the jack of all trades or beer-brewing French noodle cow among sleeping bags. So I was really looking forward to putting the Grüezi Bag to the test on such an extreme tour as the winter crossing of the Hardangervidda.

PRE-EXPERIENCE

After more than 15 years of experience on mountain and trekking tours, including two and a half years of backpacking, trekking and adventure travel during a break, I had already put a few sleeping bags through their paces. These included week-long treks, but also long-distance trails lasting several months with tent and sleeping bag, mountain expeditions to 5,000 and 6,000 m as well as winter nights under the Northern Lights above the arctic circle. And with almost all sleeping bags, the same problems arose.

On the one hand, there were the temperatures in the so-called borderline or limit range and the necessary heat and insulation capacity of the sleeping bag. With my rather narrow, wiry stature, I only have a few reserves and thus probably hardly fulfill the ideal image of the average tester, according to which the temperature range of a sleeping bag is probably determined. I'm the kind of person who freezes easily in my sleeping bag. And certainly one of the kind whose body has even more trouble generating enough of the warmth it needs to warm the sleeping bag from top to bottom in situations where it's already exhausted from the day's toil. My most common problem has always been the foot area. Once I had cold feet, I rarely got rid of them and on tours where it was extremely cold and the limit temperature range of the sleeping bag was scratched, either I had ice feet in the sleeping bag from the start or I woke up at some point in the night because my feet were freezing. A second pair of merino socks or an additional thermal liner for the sleeping bag usually didn't help either.

Not -30 °C, but we had temperatures of down to -25 °C at night: an endurance test for the sleeping bag

The next problem was a very banal one: I kept slipping off my inflatable sleeping mat while I was sleeping. Since I'm often very light and have a compact pack size when I'm on the go, I rarely carry a foam mattress around with me, except in extremely cold conditions. However, as a rule, only such sleeping mats have a profile that is not smooth. Inflatable sleeping pads usually come with a nylon surface and a low structure. If I moved at night - and I move a lot and like it - I gradually slipped off the mat in the combination of the smooth nylon surface of the sleeping mat and the usually just as smooth surface of the sleeping bag and thus into an area where the necessary insulation from below was simply missing.

The third problem is also based on my nocturnal movement. After all, I also like to turn around. And so far all my sleeping bags have always turned happily – at least in part. Most of the time I ended up in a sleeping bag so twisted that I lost any sense of comfort or I was desperately looking for the zipper in the morning. Of course it wasn't in the usual place. This became even more problematic with models that, in order to save weight, saved in certain areas of the sleeping bag with insulating filling in the area on which you lay. If the sleeping bag turned, then this area was on top or to the side and I started to freeze again.

I'm sure you all know the last big problem: the zipper. Sure, I always got him stuck at the most impossible moments. And by that I hardly mean sorting the sleeping bag away after airing it out. No, I mean especially the moments when you want to pull your sleeping bag up to the very last tooth of the zipper strip because of the cold or when you have to get up at night because you have an urgent need. Those were always the moments when I usually caused the zip to jam several times with the lining of the sleeping bag... In addition, the zip was of course often the cold bridge in the sleeping bag. Quite often the zipper itself was a problem, as at some point during the night it hung in my face like the cold tip of an icicle.

THE FIRST IMPRESSION

I received the package with my new Grüezi Bag a few days before the flight to Norway and thus before the winter crossing. And to be honest, I was super excited to see the brand's flagship product. In the days leading up to the tour, I spoke to Markus, the founder and CEO of Grüezi Bag, who explained a few things about the sleeping bag to me, in particular what thoughts and considerations went into the development of the Biopod Down Hybrid Ice Extreme and what sustainable strategy Grüezi Bag is pursuing in the manufacture of its products. What I also really liked was the openness to any recommendations as to how the sleeping bag could be further developed.

The Biopod Down Hybrid Ice Extreme 190 W

Now for the unpacking! So, the sleeping bag – in beautiful anthracite with a clearly visible white zip and an elegantly embroidered logo on the side - first of all it comes in the attached, large storage bag, on which the Grüezi Bag logo is also sewn. A compression pack sack is also included, with which you can compress the sleeping bag – if necessary – to a much smaller pack size. Since I was supposed to pull a material sled, the so-called pulka, behind me on the winter crossing, the pack size was less important for me, at least for this tour. Nevertheless, I was interested in how much the sleeping bag could be compressed for later tours with the Grüezi Bag, where this should play a greater role. And it's amazing. When unpacked, the sleeping bag bulges so much due to the filling that it initially seems huge, given the extreme conditions for which it is made. Then it can be packed down to a diameter of only about 20 x 30 cm using the compression pack sack supplied. One or the other may know this from compressible down jackets. In any case, I'm always amazed, and that's the case here, too. From a winter bivouac I did in the Alps after my return from the Hardangervidda, I now know that I can pack the sleeping bag down to about the pack size of my previous three-season sleeping bag. Unbelievable. And even the compression stuff sack is of a high quality. I've already experienced others and have few concerns here that a belt or something similar might tear.

The sleeping bag itself is incredibly large due to the filling, but above all it is cosy. Shake it up a few times and I already had the feeling that I would be able to sleep on the clouds: totally comfortable and soft. It should be a pretty nice feeling to crawl into the Grüezi Bag on the tour in double-digit minus temperatures. The wonderfully puffed down filling would -   I was convinced of that ensure a lot of sleeping comfort and a pleasant sleeping climate. In my experience, down simply has a clear advantage over synthetics. And here the down is combined with a layer of the purest alpine wool for a drier sleeping climate. I'm not familiar with this from any other sleeping bag and it should probably be a unique selling point of the Grüezi Bag. You can recognize these sleeping bags by the product name Downwool.

Of course, I also tested it immediately after unpacking and for me with my 1.80 m height the length of the sleeping bag of 1.90 m and also its cut was optimal. I immediately had a pleasant feeling of freedom of movement. In addition, I was able to move around in the sleeping bag without any problems, without it moving and twisting at the same time.

So my first impression was really good and to be honest, rarely has a product made it so right away. That gave me a very good feeling. What had my tour partner and I been thinking about in the run-up to the tour! From the exact route through the Hardangervidda, from the arctic conditions to be expected, to the type of physical and mental preparation, to the type and, above all, the quality of the necessary equipment. We'd put a lot of effort into tackling something we hadn't even known a few weeks earlier - I hadn't been a big cross-country skier in my life, nor had I ever ridden a pulka - and now, just before the tour, I had a really good feeling about the piece of equipment that, to be honest, was one of my favorite pieces of equipment. Nevertheless, I took a thermal sleeping bag liner as a backup – we had to reckon with temperatures far beyond the temperature limit of the sleeping bag. With this I could have increased the heat output of the Grüezi Bag by a few degrees Celsius in an emergency.

THE BIOPOD DOWN HYBRID ICE EXTREME IN PRACTICE

Of the five nights we spent on the tour, we slept three in the expedition tent, the coldest of which was -25°C. I was really curious in advance what the sleeping bag would do in practice. The tension was all the higher, perhaps even giving way to a slight tension, since my tour partner had borrowed a sleeping bag from an expedition outfitter for our tour, the temperature of which was another ten degrees below the range of my sleeping bag. The impression of the higher insulation capacity was reinforced because the sleeping bag he had rented was more than twice as heavy as my sleeping bag in terms of packing volume and weight. However, his sleeping bag was also a synthetic fiber sleeping bag, which is usually significantly heavier for the same insulation capacity and also compresses less. If I was still unsure about the heat output, it was completely gone after the first night outdoors with nothing but snow and ice around us.

With backcountry skis, expedition tent and the Biopod Down Hybrid Ice Extreme on 125 kilometers through the ice

To protect against the cold from below, I slept on a combination of two sleeping mats: one made of foam at the bottom and an inflatable all-season mat on top. Then the Grüezi Bag. And every time it was an absolutely cozy and cuddly warm feeling to crawl into the Grüezi Bag. No tightness as I was used to from other sleeping bags. And even with all the electronics that I took with me in the sleeping bag to protect against the cold, the wide comfort cut gave me all the freedom of movement that allowed me to sleep comfortably. The hood could be adjusted snugly to my head without being intrusive, and a wide, cuddly bulge at the opening prevents the cold air from drawing into the sleeping bag from above. 

That first night outside it wasn't quite -20°C and I slept comfortably warm. Incidentally, only a short time after I had preheated my typical problem area, the footwell of the sleeping bag, to a really comfortable temperature using the integrated heating element, to the delight of my feet. All you need is a standard power bank, which I had with me anyway. In the chest area of ​​the sleeping bag there is an inner pocket behind which there is a USB connection for operating the heating element with the power bank. Let it run for 20 minutes and it will be pleasantly warm. It wasn't just my tour partner who envied me, but also everyone else I've told about the Grüezi Bag.

When it's cold, the blood vessels in the outermost limbs, i.e. in the hands and feet, constrict much faster than in the rest of the body. For me, this sometimes takes what feels like a record speed. And since a sleeping bag can only store the heat that you develop yourself in the sleeping bag, this is a problem, especially in the foot area, as already mentioned above. With the integrated heating, I got warm feet pretty quickly and, to be honest, I hardly noticed that a lot of energy was wasted from my power bank. 

Since the temperature dropped below the limit temperature range of the sleeping bag on the first night, I initially wore a few layers of merino underwear in the Grüezi Bag: short merino shorts under long merino underpants, thin merino liner socks under insulating merino socks of extreme strength 800, a long-sleeved merino shirt on top, and a warm fleece jacket over that. And while my tour partner shivered in his sleeping bag in much thicker gear, including an additional down jacket, I gradually took off one piece after the other during the night - without twisting the sleeping bag. Until finally I was only wearing one layer of Merino. Unbelievable how much heat the sleeping bag stored! I was and still am completely enthusiastic.

The second night was the coldest of the tour: -25 °C and this time with two layers of merino wool and a merino face mask, but still without a thermal liner. The absolute endurance test of the tour! Temperatures that matched those in a 4-star freezer and were 10 degrees below the sleeping bag's temperature limit... according to the data, the sleeping bag shouldn't be able to do that anymore without me constantly freezing. And I, exhausted from a hard day in the snow and ice,… felt right in the sleeping bag and only shivered for a few moments of the night. And despite the extreme temperatures, my sleep was still restful on the night with the lowest temperatures of the tour. The sleeping bag has absolutely reliably proven that it retains heat even in extremely cold conditions. And I didn't feel a cold bridge, nor did I have to struggle with an ice-cold zipper on my face thanks to such well thought-out details as the drawstring pocket for stowing the zipper. If there was anything cold, it was falling snow crystals that had formed on the wall and ceiling of the expedition tent during the night due to our condensing breath. And if I hadn't taken my drinking bottle into the Grüezi Bag around midnight, which I forgot outside of my sleeping bag and was almost frozen to a block of ice, I might not even have shivered a bit during the night. Because when I did that, it was in those moments when I came against the cold drinking bottle with my body and thus triggered the opposite effect of a hot-water bottle.

Temperatures equal to those in a 4-star freezer. The Grüezi Bag did more than it promised

The other problems that I knew from my previous sleeping bags were also solved in the Grüezi Bag: the three straps made of anti-slip knobs on the back of the sleeping bag really reliably ensured that I didn't slip off the sleeping pad during the night as usual. I don't want to miss that anymore! How often have I woken up in cold weather conditions because I had slipped off the rather narrowly cut sleeping mat, which after all had to fulfill the insulating function from below. So those days were over! Problem: checked!

And the combination of anti-slip nubs and the wide fit of the sleeping bag actually allowed me to move around in the sleeping bag at night without it twisting and turning with every movement. It doesn't matter whether I wanted to roll over, lie on my side, draw my legs up or stretch them out again, take off a pair of socks or an overworn top... the sleeping bag gave me all the freedom of movement I needed without getting tangled up in the process. Next of my problems: checked!

With the Grüezi Bag through the vastness of the Hardangervidda

What surprised and pleased me the most, however, was the zipper. The retention strap and anti-snag zip system worked flawlessly throughout the tour, so I couldn't even get the zip to get caught in the sleeping bag lining. I knew that very differently and - oh my God - what had always bothered me... Problem: checked!

Incidentally, on the tour we had ice-cold but dry conditions throughout, so I was not able to finally test the function of the AlmWolle layer, which as the outermost layer of the sleeping bag is supposed to protect the down from moisture. In the meantime, however, I have experienced wetter conditions on the winter bivouac that was held after the tour and can confirm that the sleeping bag has not lost any of its thermal performance despite the partly wet outside.

As an additional feature, which I haven't mentioned so far, the Grüezi Bag has an outside pocket at shoulder height next to the logo, in which a mobile phone or similar can be stowed. A detail that, although not essential, increases the function of the sleeping bag even more. There are also other well thought-out details, for example the zips are kept white throughout so that you can see them better in the dark.