Zpacks 10F Mummy Sleeping Bag Review

JUMP TO: SPECS  |  PROS & CONS  |  HOW IT PERFORMED  |  FEATURES  |  ACCESSORIES  |  SUMMARY

Author: Steve Edgerton | Updated: Jan 20, 2024
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The Zpacks Mummy Sleeping Bag stands out among ultralight sleeping bags and quilts for its versatility. It combines the warmth and coziness of high-loft mummy bags with the ventilation and packability of quilts. This combination results in a sleeping bag that is an excellent choice for almost all three-season conditions, and even some light winter use. 

But any bag that is this light and warm, while still including features like a full-length, two-way zipper and an adjustable hood, comes at a cost. The Zpacks Mummy Bag is one of the most expensive lightweight sleeping bags at this temperature rating. It also saves weight by employing an extremely thin 7-denier nylon shell. Punctures and micro tears are nearly inevitable, even for the most diligent hikers.

Although it is unlikely to win any durability awards, the Zpacks Mummy Sleeping Bag’s exceptional warmth-to-weight ratio and full-featured versatility are uniquely suited for light and fast mountain adventures where short-term performance matters most.

SPECS

 

TEMPERATURE RATING: 10 F / -12 C (also available in 20 F / -7C version)

TOTAL MEASURED WEIGHT: 27.1 oz / 768 g (Standard-Medium size)

FILL WEIGHT: 19.8 oz / 561 g 

MATERIALS: 900-fill RDS-certified goose down, 7D ripstop nylon shell

 

 

PROS

  • Full-length 2-way zipper maximizes versatility

  • Off the charts warmth-to-weight ratio

  • Super packable

CONS

  • Very expensive

  • Thin and fragile nylon shell lacks durability

 

HOW IT PERFORMED

WARMTH: By weight, the 10 F sleeping bag is nearly 75% 900-fill power goose down. Its warmth-to-weight ratio is top-notch, and its coziness is complemented by a cinchable hood and draft collar. In temperatures near freezing, I quickly began to cook. However, the 10F rating is probably aspirational — camping out on nights that cold with only this sleeping bag is not something you want to test too closely.

In typical summer conditions, I usually unzip the bag at my feet: being able to let my feet and legs splay freely while enjoying the warmth of a sleeping bag is easily my favorite feature of this Zpacks bag.

 

It is easy to moderate your temperature in the mummy bag thanks to the two-way zipper.

 

COMFORT: The inner and outer shell of the sleeping bag is constructed from soft ripstop nylon that is comfortable on bare skin. The adjustable mummy hood and puffy draft collar deliver the classic cozy mummy bag experience. As a side sleeper, I find the width and the foot box shape to be accommodating and never feel constrained or claustrophobic.

 

No, not the Cookie Monster: just a really warm and cozy ultralight mummy bag.

 

WEIGHT & PACKABILITY: The sleeping bag weighed in a hair over 27 oz. This makes it one of, if not the lightest sleeping bags rated to 10 F. Along with maximizing its warmth-to-weight ratio, the high fill power down works with the thin nylon lining to maximize packability. Its packed size in the included Dyneema dry bag is 11” x 6”: pretty impressive for a bag this warm.

 

The sleeping bag packs down small in the included Dyneema dry bag, though it becomes somewhat rigid and awkward.

 

VERSATILITY: For many hikers, a 10 F sleeping bag would be too warm for typical three–season use. But the stout temperature rating makes the Zpacks Mummy bag an appropriate choice in the alpine and even in light winter conditions. The full-length, two-way zipper creates versatility in warmer temperatures. It is possible to open the bag at the feet to vent heat or open the sleeping bag entirely on warm nights. 

Warmth and great venting, yet still lightweight and packable? Sign me up. Given this versatility, I’m not spending many nights in the backcountry where this bag isn’t fit for the conditions.

 

Use the sleeping bag as a full-on mummy bag, a quilt/blanket, or even as a cape for frosty mornings at camp.

 

DURABILITY: The Achilles heel of most ultralight gear is durability, but this is especially pronounced in Zpacks sleeping bags. The 7-denier Ventum nylon shell saves weight, but it really is ultra-thin. You’ve really got to baby this thing: avoiding the zipper snags, packing it in the Dyneema dry bag, and taking extra time to clear your tent area of sticks and sharp rocks will help keep it in good shape.

Even with all those precautions, regular wear and tear is simply unavoidable, and many hikers experience micro tears, punctures, and down leakage from loose seams. I’d hesitate to rely on this sleeping bag for long thru-hikes or remote expeditions.

NOTABLE FEATURES

DOWN FILL: The 900-fill power goose down is certified by the Responsible Down Standard. It has a PFC-free water-repelling treatment, which helps it retain its insulating power in wet conditions. 

TWO-WAY ZIPPER: The two-way zipper extends along the entire right side of the sleeping bag and across the footbox. It can open fully and be used as a blanket or opened to any degree to moderate your temperature on warmer nights.

 

The two-way zipper extends across the foot box and both ends can be fully opened or closed from either end.

 

ADJUSTABLE HOOD: The hood and collar can be cinched separately along the same drawstring. You can tighten one or the other, or both simultaneously to bask in the full-mummy experience on those frigid nights.

 

A single drawstring is used to tighten the hood and draft collar: either individually or at the same time.

 

DYNEEMA DRY BAG: The sleeping bag comes with a Dyneema dry bag, which is a nice perk. Dyneema is waterproof and durable, adding protection from moisture and tears while the sleeping bag is in your pack.

OPTIONAL ACCESSORIES

REPAIR TAPE: If you’re not already packing some gear tape in your repair kit, you’re going to want to start when relying on a sleeping bag with a razor-thin 7-denier nylon shell. Pick up some Zpacks Nylon Tape Strips, made from the same Ventum nylon as their sleeping bags and wind shells.

ZPACKS INFLATABLE PILLOW: Maybe I’m just getting old, but I consider a pillow as mandatory, not an unnecessary extravagance, even when going ultralight. Round out your ultralight sleep kit with a Zpacks Inflatable Pillow, weighing in at a mere 1.4 oz.

SUMMARY

For short hiking and fastpacking trips in the alpine, where I’ve experienced nighttime lows of 20 F and 50 F on the same trip, the Zpacks Mummy Sleeping Bag is an option I am grateful to have. It provides the extra warmth that can keep you alive through temperamental and unpredictable mountain weather, yet it is light and versatile enough to serve just as well on warm summer nights. 

A warm, mountain-ready ultralight sleeping bag is a rare thing, and the Zpacks Mummy bag is priced accordingly. You could save some cash (and weight) by opting for the Zpacks Solo Quilt instead, but you’ll lose some of the warmth and versatility of a fully zippered mummy bag. 

Price tag aside, the fragile ultralight construction is the sleeping bag’s only other real downside. Dropping so much cash on a bag without decade-plus durability can be a tough sell. That said, although it is not my go-to for remote or long-distance trails, the Zpacks Mummy Sleeping Bag is nevertheless a versatile, high-performing option for shorter, fast-paced trips when light packs and big miles through unpredictable conditions are the name of the game.

DISCLOSURE

Zpacks provided me with a free sample for this review – but the views expressed here are all my own. The review might also contain affiliate links, which help us keep churning out more content.

MORE INFORMATION

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Happy hiking and take care out there in the wild!