Mammut Sleeping Bag Review - Ajungilak Kompakt Winter (Video)

Winter Mountaineering - Testing Sleeping Bag

The guys at were kind enough not only to reply to my tweets and emails but they also sponsored me with winter sleeping bag - Ajungilak Kompakt Winter. This was rather unexpected since most of the big companies don't even reply to their emails - ever!

Thumbs up for Dominik Ryser, Web Content & Social Media Manager at Mammut Sports Group AG, who took care of this!

So here's my review for Mammut Winter Kompakt sleeping bag:

Mammut Sleeping Bag

Appearance and design

Neat is the best word to describe the bag. From the color combination to materials used - it all comes together very well.

The yellow compression sac is easy to spot in any kind of environment, which might be helpful if you accidentally dropped your bag on a slope while preparing for overnight bivouac or camping.

Red color inside the sleeping bag itself is not only sexy but it has a psychological effect regarding warmth. Since red is associated with fire you have this feeling that you're gonna be warm once you get in. Of course this is not necessarily true but it's a detail that gets you prepared for a comfy sleep (and it's one of those small things that you cannot put your finger on that adds up and make you love your bag).

Modern sarcophagus shape of the sleeping bag, follows your body line and ensures you don't loose heat. This means you won't have too much room to move but that's the case with any sleeping bag anyway. The fit is neither tight nor loose, it's just right.

Sleeping Bag Compression Sack


Everything's simple about this bag. That's valuable, considering you have to work with it in low light conditions (assuming you prepare for camping after sunset) or in frost (you wanna go inside as fast as possible and NOT do intricate maneuvers). We expect stuff to be simple to use - the people at Mammut took that into consideration.

You have two inner cords, that are both easy to operate:
  • one that tightens the collar of the bag
  • one that tightens the hood
The cord itself is made out of a soft but resistant nylon fiber. It doesn't feel like a cord, but more like a velvet ribbon. 

Sleeping in low temperatures can be done even with poor quality sleeping bags if you tighten the neck collar of your bag correctly (and if you wear enough clothes on you). 

What I love about this bag is the nice system that enables you to close your collar. It's easy and effective - with the velcro cloth (loops) which is sandwiched between two other velcro hooks tape. The hooks are fleece friendly, that is you won't get your clothes caught in them. And since the collar is very important for heat retention while sleeping, I find it nice to be able to operate it fast and easily.

One of the worst things you can do during winter camping is to leave your boots outside... You don't wanna do that! You'll end up with two pieces of frozen leather that are almost unwearable.

What you want instead, is to keep your mountain boots warm and soft (not frozen) and for this you need to have them inside your sleeping bag overnight. Mammut Kompakt Winter has enough room in the feet box (the lower part of the bag) to accommodate a pair of winter mountain boots. And if you have plastic boots, then you can only take the inner insulated boots and have them inside. Just put them in a plastic bag as to protect your sleeping bag from snow or dirt.

Nice and snug hood which you can close in as much as you want - just don't exaggerate. Some people experience the sleeping bag claustrophobia (to some extent I do too) due to lack of space and air. Keep your hood open as get enough air and to keep the warmth within. Since I sleep with the tent's flysheet over my face, I create a micro climate where the air I breathe is not as cold as the air outside - but when I want to take fresh air I usually find the air to be too cold (in winter) and then I close in the hood as much as possible.

The zipper is well insulated with a wide flap that ensures you don't loose any warmth during cold nights (much wider than in my old sleeping bag).

Mammut Winter Kompakt Sleeping Bag

Temperature rating

The sleeping bag is rated -9° Celsius (15° F) for men and -3° (26° F) Celsius for women (are men more resistant to low temperatures than women?!).

According to the internet, when I was up in Fagaras Mountains, testing the bag, there were anywhere between -15° to -20° Celsisus (frosty night all over Romania actually)  down in Brasov (my home city) and Fagaras. So my guess is that it was a bit warmer, from -11° to -15°, up in the forest, at approximately 1800 m altitude.

Now you may ask: Were you cold during that night, sleeping outdoors on the spruce twigs?

I wasn’t. But I was dressed with all my clothes (except the waterproof jacket). Just before the sunrise I felt a small hint of coldness but I wouldn’t say I was cold. So, assuming there were -15 degrees Celsius, let’s say my clothing provided the extra insulation for those extra low degrees (from -9° to -15°).

This was the first time I was actually warm and snug sleeping outdoors in wintertime. So I may be a bit biased since this is the best sleeping bag I’ve ever had but the rating of minus 9 degrees Celsius (comfort) is honest.

I cannot tell you much about the filling of the bag since all that terminology is foreign language to me (you can read more about MTI®13 filling here). Ajungilak Kompakt Winter is a synthetic sleeping bag, filled with hollow fiber which traps air, and thus provides good insulation. However the weight - volume ratio (capacity to trap air) of hollow fiber are inferior compared to down.
  • The high-performance MTI®13 filling combines lowest weight, best compressibility and maximum insulation
  • Box Construction for more loft, better fit and increased insulation capacity
  • Excellent weight/insulation ratio
  • Silky-smooth fabrics
  • Ergonomic Foot increases comfort and insulation
  • Traveller: ultracompact cover sleeping bag with Smartlink
Source: - Ajungilak Kompakt Winter


Depending on the size of the bag (according to your body height) the weight ranges from 1750 grams to 2100 grams. Mine is 195 cm long so it's 2 kilos heavy.

I've never had a bag lighter than this so this is nothing new to me. Considering the ergonomic shape, the small cool features and the temperature rating, the weight that comes attached is not a bad trade.

However, I'd like to have a lighter bag for those technical winter mountaineering tours where I also carry a rope, harness, crampons, snowshoes and what not. A lighter backpack means easy climbing and faster ascents.


A good non pretentious bag for winter tours where lightness is not the most important aspect.

You can count on it in low temperatures (as low as -15 ° C for comfort I'd say - with a few extra items of clothing on you).

The synthetic filling means that you don't have to worry too much if your bag gets wet due to water, snow or ice - unlike down bags which require more care regarding exposure to moisture. If it gets wet, make sure you leave it out in a ventilated place before storing (and store it loose, NOT inside the compression sack).

Wicked compressibility with the included compression sack which allows you to drastically reduce the volume of your bag (small pack necessary while carrying it in your backpack).

Overall - a cool sleeping bag to have! Thanks Mammut!

Check out more pictures below:

Compression Sleeping Bag


4 Season Mammut Ajungilak Sleeping Bag

Winter Sleeping Bag

Mammut Logo on Sleeping Bag

Hood Stopper in Sleeping Bag

Pocket Inside Sleeping Bag

Sleeping Bag Mammut Details

Reflective Stripes in Mammut Sleeping Bag

Hood in Sleeping Bag

Hollow Fiber Sleeping Bag

Neck Collar in Sleeping Bag

Sleeping Bag Collar

Mammut Sleeping Bag Fabric Detail

Sleeping Bag Hood

Sleeping Bag - Mammut Kompakt Winter

Velcro in Mammut Sleeping Bag

Sleeping Bag Insulation

Enjoy outdoors!

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  1. Very thorough review! Pretty much everything I've had of theirs is high quality and really functional Good to hear you found the same.

  2. Thanks for the detailed review Constantin...and for putting Mammut on my radar.

  3. @Kovas -Thanks! Yup, Mammut is highly popular in Europe and they manufacture premium gear. I'm privileged to be sponsored by them.

    @Manny - Thanks, no problem! I hope your radar shows how Mammut is approaching your base camp. :-)

  4. Great review Constantin, nice video also...

    Keep up the good work ;)

  5. Very nice scenery in the video Constantin. Good review. Keep in touch.

  6. Thanks Casey! Yup those are my favorite mountains for winter mountaineering tours. Our little corner of "Alaska". :-)

  7. Gabor, nice review in an elegant fashion!
    I enjoyed reading it and that is certain of you used this sleeping bag and speak the words of experience. (I would like you to review one of the Exped insulated sleeping pads next as part of your sleeping system).

    Some additional thoughts to your review that the compression sack can be used as a pillow stashing your waterproof jacket in it. Also the rating on the sleeping bags are more like emergency/survival ratings meaning that you will likely get cold in it around those temperatures, but not dead. A good sleeping bag liner like Sea to Summit can help with keeping the inside of the bag clean and adds to the temp rating.

  8. Thanks Kornel!

    Good point about the pillow. :-) Yeah I guess I could use a liner for extra comfort and for keeping the bag clean.

    If you have an Exped sleeping mat and wanna share your thoughts about it, shoot me an email. I'll publish the review on your behalf. Must see if they wanna sponsor me. :-)


  9. Terrific job on this review! Looks like a great bag. Thanks.

  10. Thanks! Yeah, it's a cool bag to have!

  11. Hi mi friend. I have to thank you for the reviw. Thanks to you i got one a year now and i hade the chance to try it out in Balea Lac on 26 th of December 2011 and we went down to -25 in the night time. i had a flece liner , and mi Mammut down jacket on me but i slept like a log till 9 am. it is a great bag for the money and i will not change it for nothing in the world.the only problem i have with it is the zip wich is harder to operate in the top end bit but exept this litle one is perfect for me. I hope oder people will taste the great products from Mammut.I did convert to Mammut more then 5 years now and not regrt a bit. Keep it safe

    1. Yup, Mammut makes top gear.

      I guess that inner liner and the down jacket were worth having at minus 25 Celsius. :-) I didn't test it in such low temperatures yet but there's still time (hopefully this will be in Fagaras mountains).


  12. My Mammut Anjungilak is truly a terrible sleeping bag. I has the balkiest zipper I have encountered in 35 years of backpacking. It has given me repeated problems. Finally one night when I desperately needed a potty break, I could not unzip the bag and ultimately pulled the zipper off track to escape the trap. I still cannot get the zipper properly tracked. Also it is an undersized bag. At 5'8", I do not consider myself a large man. But the medium size bag is too small. What a waste of money! ):

  13. It is possible to compress it much more than on the pics. Anyway, great sleeping bag but I've never tested in temp below 0. When there's 10 outside in this sleeping bag is bit too warm (in tent).

  14. Yup, you can compress it to half it's normal size if you pull hard on the slings.


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