This is a gear review of the brand new Zpacks Mummy Sleeping Bag that was released in early 2023.
The Zpacks Mummy Sleeping Bag is the latest sleeping bag released by Zpacks as they go about updating and upgrading their entire sleeping bag range. Like the recently reviewed Zpacks Zip Around Sleeping Bag, it features a full wrap-around zip that can effectively turn this from a Hooded Mummy Sleeping Bag into a Backpacking Quilt.
The Zpacks Mummy Bag comes in two temperature ratings, 10F, and 20F.
I took the soon-to-be-popular 10F mummy sleeping bag out to test and review. Keep reading to find out more.
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How We Tested
Zpacks Mummy Sleeping Bag in this review has been extensively evaluated and researched by the expert author who has more than 30 years of experience in Thru-Hiking, Backpacking, and Hiking. He also spent several years managing a hiking retail store and is regarded as an expert in this field. It was supplied by the manufacturer for this review. It has been rigorously tested by the author in all kinds of weather on multiple overnight backpacking trips. The research, testing, and experience of the author have combined to present this honest and unbiased review. Read the Review Policy for further details.
In-Depth Review: Zpacks Mummy Sleeping Bag Specifications 2024
Overall Weight: 23.2 oz / 659 grams (standard width / medium length)
Shell Weight: 7.6 oz / 217 grams
Down Fill Weight: 15.6 oz / 442 grams
> Can be unzipped and used as a quilt
> High-quality 900 Fill Power Water Resistant Goose Down
> Overstuffed baffle with 30% more down
> Come with a large waterproof stuff sack
> No Lofting Bag
Overall Weight: 27.7 oz / 785 grams (standard width / medium length)
Shell Weight: 7.9 oz / 224 grams
Down Fill Weight: 19.8 oz / 561 grams
> Can be unzipped and used as a quilt
> High-quality 900 Fill Power Water Resistant Goose Down
> Overstuffed baffles with 30% more down
> Come with a large waterproof stuff sack
> No Lofting Bag
The Zpacks Mummy Sleeping Bag is not only an ultralight sleeping bag but can also be used as a backpacking quilt due to the full wrap-around zip. This makes this sleeping bag one of the most versatile sleeping bags on the market at the moment.
Like most of the Zpacks sleeping bag range, it comes in 4 colors, namely green, blue, black, and my favorite orange. It comes in two widths, the standard, and the broad. In this review, I tested the standard width and found it to be a perfect width that allowed me to move around inside the sleeping bag without feeling cramped.
At the moment it only comes in the 10F and 20F temperature ratings. I used and tested the 10F for this review but the information presented will also be relevant to the 20F version.
Several features set this apart from most of the other ultralight sleeping bags and quilts on the market.
Firstly, it has a full zip that allows the bag to be completely unzipped and used as a quilt.
Secondly, it is overstuffed by 30% extra 900 loft water-resistant down. I love this feature. It allows you to use the bag more times than most other bags before it needs to be washed. Perfect for the long-distance thru-hiker.
Thirdly, Zpacks has been able to produce a quality sleeping bag that is warm, ultralight, and has best-in-class versatility.
When compared to other ultralight sleeping bags, the full-length zip increased the weight of this mummy sleeping bag slightly. However, the ability to use the bag in a more varied range of temperatures and situations seems to be a good compromise.
The anti-snag zip worked well thanks to a strip of webbing that runs the length of the zip, and the draft collar does a decent job of preventing drafts from entering.
The Zpacks Mummy Sleeping Bag comes with an oversized Dyneema stuff sack. Not only is the stuff sack waterproof but the large size makes it easy to pack up the bag in the morning. Although the staff sack is quite large, it can be compressed quite a bit by sitting on the stuff sack to push the excess air out of the stuff sack. I was able to reduce the pack size by half when using this technique.
Overall, the brand new Zpacks Mummy Sleeping Bag is the best full zip mummy sleeping bag for 2024. The versatility of this mummy bag allows it to be used as a backpacking quilt and is sure to be very popular on thru-hiking trails around the world in 2024 and beyond.
Down type / fill power
The Zpacks Mummy sleeping bag is stuffed with 900-fill power goose down. They use water-resistant PFC-FREE DownTek which allows you to use the sleeping bag in damp environments with a little more confidence. This is right up there with some of the best quality down used on any sleeping bag at the moment, very few are using a higher loft than 900 fill power.
What makes this sleeping bag better than most of the competition is the overstuffing of the baffles. With 30% extra down in the baffles it allows the bag to do a better job at staying lofted in difficult situations such as damp weather, or when your bag is very well used such as on a thru-hike.
When your bag is dirty, soaked with weeks and months of sunscreen, body oils, and more it will lose a lot of its loft and not be as effective at keeping you warm. The extra 30% of fill will ensure maximum loft when other bags are starting to lose their loft. Thru-hikers who might use this bag for 100-150 nights before washing it will love this feature.
Like almost every sleeping bag on the market right now, the goose down is Responsibly Sourced and Responsible Down Standard Certified.
Let’s take an in-depth look at how the Zpacks Mummy Sleeping Bags are made with features such as the Inner and Outer Shell fabrics, zippers, baffles, draft tubes, hood, and weather resistance.
Outer and Inner Shell fabric
The external face fabric and internal liner of the Zpacks Hooded Mummy Sleeping Bags are made using a 7 Denier Ripstop Ventum Nylon. This is one of the lightest fabrics used on any sleeping bag that you can buy in 2024.
It is coated with a PFC-free DWR coating to prevent drops of water from entering the bag. When you take a look at this fabric it is almost see-through and extremely lightweight.
As mentioned above, there is a PFC-free DWR coating on the sleeping bag fabric. I tested the water resistance and quality of the DWR coating. While I did not sleep outside in rain I poured several liters of water on the sleeping bag, and I can confirm it will provide a decent level of water resistance.
The Zpacks Mummy Sleeping Bag would be good enough to sleep outside under the stars when there is a very small amount of condensation overnight. As mentioned above, the 30% overstuffing of down will assist in keeping it as lofted as possible.
As you can see from the photo below when I tested the DWR coating on the fabric, the water beaded quite well. It will get in through the stitching and where the zips are but it is reassuring to know that Zpacks use water-resistant down. This down would only be able to absorb about 20% of the water. Very impressive.
Disclaimer: I do not recommend that you pour several bottles of water over your sleeping bag to test its water resistance nor sleep outside in the rain!
Zpacks use a combination of vertical and horizontal baffles.
The vertical baffles are used on the upper part of the bag that corresponds with your upper body. They do a good job of preventing any down from shifting during the night. If you are a side sleeper or move around a lot during the night, that means this design will work well for you.
The lower section uses horizontal baffles. These styles of baffles do a good job of locking in as much heat as possible. The horizontal baffles at your feet are not sewn through to maximize the loft and warmth to your feet. If you suffer from cold feet then you will like this design.
If you suffer from really cold feet Zpacks have you covered with their Goose Down Socks.
Overall, there is little to criticize and lots to praise with the baffle design, which combined with the overstuffing of each baffle leads to me regard this sleeping bag among the best of the best.
Zips and Draft Tube
The Zpacks Mummy Sleeping Bag is the newest addition to the Zpacks sleeping bag range as it was only introduced in early 2023.
The zips and draft tubes work as expected and do a good job.
Along the zip, there is a length of internal webbing that is both lightweight and sufficient enough to prevent most snags. If you try hard enough you will snag the zip but in most situations, it works well.
Along the length of the zip there is a draft tube which does a good job. There is no draft tube around the collar or the hood like many other sleeping bags. But the bag still seems to do an adequate job of keeping the warmth in.
The hood on the Zpacks Mummy Bag is very basic in design and function. There is no draft tube around the hood or collar but the basic design seems to do a good job of keeping the heat in.
The dimensions of the hood are generous enough to be able to wear a beanie, down balaclava, or expedition-weight down jacket without issue.
The toggles are lightweight and basic but work well. When sleeping on your side, stomach, or back the hood stays in place and performs well.
Overall, the hood is not as good as some other sleeping bags but the hood is warm and the basic design does the job of keeping the overall weight of the sleeping bag as light as possible.
The Zpacks Mummy Sleeping Bag uses an impressively lightweight Dyneema stuff sack. It is waterproof and quite large. Having a large stuff sack makes it easy to pack the bag in the morning. No need to try and squeeze it in perfectly every time. Just shove it in any way you like and it will work.
The stuff sack does not use compression straps. You can sit on the stuff sack after putting the sleeping bag inside. This will remove the air and will decrease the size of the packed-up sleeping bag to about half its size. After sitting on the bag, do up the clips, and it will pack to a small size.
The photo below doesn’t do justice to just how small the 10F sleeping bag can compress. It can go smaller than the photo below! Great for the days when you need all the room possible inside your ultralight backpack.
The Zpacks Mummy Sleeping Bags come in three lengths and two widths. The widths are generous and sufficient for most people to not feel too cramped. I tested the standard width and found it perfect for my body size, even when wearing an expedition spec down jacket. If you are a larger build or want extra room, you can consider the broader width. Check the website for the exact specs.
Overall, the sizing of the bag is great and exactly as mentioned on the specification sheet on their website.
Zpacks do not test their bags to EN or the newer ISO 23537 Standards. They use their temperature ratings based on their own experience. They estimate the temperature ratings to be close to the ISO Rated ‘Limit’ Rating of a Sleeping Bag, which is sometimes called the ‘transition’ rating.
I was unable to test the bag in very low temperatures. So I will update this section in the future. But judging from the amount of down used in the bag, combined with the 900 loft, and the quality of the baffles, I would believe that the 10F and 20F ratings should be quite close to the limit/transition ratings for most people.
Caring for your Zpacks Mummy Sleeping Bag
The Zpacks Mummy Sleeping Bag is not the cheapest sleeping bag on the market, so it is worth taking care of it. One of the best things you can do is wear clean backpacking base layers to bed to prevent sweat, dirt, and body oil from penetrating the liner of the sleeping bag. You can also use a sleeping bag liner to keep it clean.
How to store your Zpacks Mummy sleeping bag
Zpacks do not provide a lofting bag, which is one thing that could be improved. When storing your Zpacks sleeping bag it is best not to leave it compressed inside the stuff sack. Extended periods of doing this can affect the lofting ability of the down. The higher quality of the down (the higher the loft number, eg 900) the more chance you have to damage the down over an extended period.
I strongly recommend storing your sleeping bag in a larger lofting bag to increase the length of service of your bag. If you do this, you will get at least 10-20 good years of use out of this bag. Especially if you take care of it and wash it when needed.
How to wash your Zpacks Mummy Sleeping Bag
Over time the Zpacks Mummy sleeping bag will lose a bit of its loft and you may start to complain that the bag is not as good as it used to be. This happens with every down sleeping bag. The overstuffing of down in this bag will mean it will outlast most other bags that are used similarly.
Maybe your bag might start to have some funky smells that seem to be a cross between a sweaty gym towel and an unwashed homeless person. If this occurs it is time to give the Zpacks sleeping bag a wash.
At the time of reviewing this product, the new Zpacks Mummy Sleeping Bag is priced at the higher end of the market. There are cheaper options out there but if you are looking for one sleeping bag to use in a great variety of temperatures then this could be the one you have been looking for.
Being able to completely unzip the bag and use it as a quilt in warmer weather removed the need to purchase several sleeping bags. And when it does get cold, zip up the sleeping bag, cinch the hood tight and you will be nice and warm.
And unlike some other sleeping bags, there do not appear to be any supply chain issues.
Zpacks Mummy Sleeping Bags Vs The Rest
This is a very new bag and compared to every other sleeping bag and quilt that I’ve tested and reviewed over the years this one stands out as the most versatile. This is perfect for thru-hiking and anyone wanting a bag to use in a great variety of temperatures.
Compared to the Zpacks Zip Around Sleeping Bag, the Mummy Bag is a little bit heavier but has a hood. This is essentially the only difference.
Compared to the Sea to Summit Spark Sleeping Bags the Zpacks do not have the same temperature ranges of bags and are not quite as comfortable. But getting the wide version of the Zpacks bag might make them equal in comfort. Sea to Summit has a slightly better DWR coating and is a bit more durable due to the heavier 10 Denier outer material.
Compared to the Therm-a-Rest Hyperion Sleeping Bag Range, the Zpacks Bag is heavier. But there is much more room inside the bag and the ability to completely unzip the bag and use it as a quilt.
Compared to the New Zealand Brand Macpac Dragonfly Sleeping Bag Sleeping Bag, the Zpacks are lighter and much more versatile. But the Dragonfly does have a much better hood, much better weather resistance, and a very different but equally good stuff sack, all of which make their bag heavier.
Best Suited Use
The Zpacks Mummy Sleeping Bags are perfect for anyone wanting an ultralight sleeping bag that can also be used as a quilt and over a wide range of temperatures.
My expert recommendation for this sleeping bag would be to use this bag for the following:
- Three Season backpacking in the Rockies or Sierra or North America with the 10F or 20F.
- Almost any thru-hike anywhere in the world, including the Appalachian Trail, Pacific Crest Trail, and Continental Divide Trail. Perfect for a great variety of temperatures.
- Three Season backpacking and hiking in the Alps in Europe or hiking the Camino. The warmer bags will be well suited to 3 season trips in most places.
- 3-season or even 4-season hiking in Australia and most places in New Zealand including the Te Araroa Thru Hike.
- If you are planning a trip anywhere in the world where you will encounter a range of temperatures and only want one sleeping bag. For example, a multi-week or multi-month trip in South America where you will be at high altitude on one backpacking trip, Patagonia for another hike, and warmer places and only want to take one bag to do it all.
With best-in-class versatility, this mummy sleeping bag can be completely unzipped and used as a backpacking quilt on warmer nights. This makes the Zpacks Mummy sleeping bag perfect for thru-hikers or someone wanting an ultralight sleeping bag that will work under a very wide range of temperatures.
Except for the price tag, there is little to fault with this bag. Having said that, I would love to see a lofting bag included to prolong the life of the bag when not in use, but that might not fit with the minimalist nature of all Zpacks products. I think in the coming thru-hike season this bag will be seen on all the thru-hiking trails and will only increase in popularity over time.
Overall, the Zpacks Mummy Sleeping Bags is the most versatile ultralight mummy sleeping bag for 2024.
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Frequently Asked Questions
Is the Zpacks Mummy Sleeping Bags any good?
The Zpacks Mummy Sleeping Bag is the newest sleeping bag on the market from Zpacks. Like all their products it is ultralight and best suited for thru-hikers or backpackers that want to carry less weight but have all the best features. The biggest thing about this sleeping bag is the full zip that allows the sleeping bag to be unzipped like a quilt.
Do Zpacks Sleeping Bags use Responsibly Sourced Down?
Yes, All the down used in Zpacks sleeping bags is ethically and responsibly sourced.
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BikeHikeSafari Gear Review Process
The author, Brad McCartney from BikeHikeSafari is a small independent adventurer and outdoor gear tester who owns and runs BikeHikeSafari.com.
BikeHikeSafari is not part of a large blog network and is proudly independent. All reviews on this site are independent and honest gear reviews of outdoor products by the author.
The author, Brad McCartney is a very experienced triple crown thru-hiker, adventurer, and bike tourer having spent 1000s of nights sleeping in a tent and sleeping bag (Read more). He was a manager of an outdoor retail store and is very experienced in what is important when using and testing gear for reviews like this.
BikeHikeSafari will never receive any money for reviews and they do not accept sponsored reviews on this website. All the comments about the gear reviews are from the author based on his years of experience. Hope this independent review was helpful to you.