Big Agnes Yock 0º Sleeping Bag ReviewMay 9, 2019
- Big draft collar
- Hydrophobic down
- Narrow fit provides efficient warmth
- Not super high down quality
- On the heavy side
- Compression sack not included
- Narrow fit uncomfortable for broad shouldered peop
The Big Agnes Yock is a classic mummy-style sleeping bag that is available in Regular and Long lengths. The design has been improved slightly for 2019, featuring different colors and a slightly different yet still generous draft collar. Whether the older model or the newest update, we have found the Yock to be an excellent down winter sleeping bag for those on a budget.
The Big Agnes Yock accompanied us to Little Switzerland in Alaska for a stormy two weeks camping on a glacier, spent a cold Thanksgiving week in Death Valley, and has been used on several other winter overnights. Every tester reported a satisfying night’s sleep. Big Agnes does not do EN testing, so it is a little difficult to compare the temperature rating of this bag to the ones with EN ratings. In practice, we found it to be on par with bags like the Therm-a-Rest Questar and The North Face Guide. The cut and fit of the Yock are on the narrow side. This shape provides efficient warmth if it fits well. We did have one broad-shouldered tester complain that he could not zip the bag fully, which reduced the warmth for him. Larger folks may find the fit of this bag unsatisfactory.
The down used inside the Yock is 600-fill, meaning it takes up less volume and is less compressible per ounce than higher quality down like the 900+ fill found in the Feathered Friends Snowbunting. Higher fill power down provides more insulation per ounce, so less can use to achieve the same degree of warmth. It is interesting to compare the fill weights (the actual physical weight of just the insulation) of the Yock – 2 lbs, 5 oz – with that of the Therm-a-Rest Questar—1 lb, 13 oz. The Questar uses 650 fill down, which is similar quality to the 600-fill in the Yock. This big difference in fill weight leads us to believe that the Yock has more insulation included inside the bag than the Questar, which could indicate more warmth as well as a little more weight.
On our scale, the Big Agnes Yock came in just under the listed weight of 3 lbs, 7 oz (3 lbs, 6.6 oz). This is closer in weight to the synthetic bags in this test than to the other down bags we evaluated and make the Yock a less appealing choice for human-powered activities. If we plan to carry a bag, we prefer to stick with one that is under 2 pounds, such as the Therm-a-Rest Questar, the Sierra Designs Nitro, or the Feathered Friends Snowbunting. However, there are plenty of winter camping adventures that do not involve carrying gear in a backpack, such as car camping or being dropped onto a glacier by a small plane, and in this case, the weight of the product does not concern us.
The Yock is given enhanced water resistance through a hydrophobic treatment on the down insulation and a water repellent finish on the shell material, both of which are fairly standard features these days. The DWR (durable water resistant) coating on the shell material, like all DWRs, will work well at first but will wear off over time. The Down Tek insulation has increased resistance to moisture, which can let the sleeper be more at peace if their bag comes in contact with condensation or light precipitation. However, hydrophobic down will not maintain its loft in a downpour like synthetic insulation, so avoid letting the Yock get drenched. The Therm-a-Rest Questar and the Sierra Designs Nitro also feature hydrophobic down and a DWR coating on the shell. We found that these bags will all resist moisture to an adequate degree, such as the condensation that is inherent in winter camping.
The Yock is the least compressible of the down bags in this winter sleeping bag test, but it is far more compressible than any of the synthetic options. Even though it weighs almost as much as the lighter synthetic models we tested, the Yock will pack down much smaller. It does not come with an included compression sack. With the addition of an aftermarket sack with tightening compression straps, it would pack down much smaller than in its nylon stuff sack.
The Yock has all the primary warmth-enhancing features expected in a winter sleeping bag: a draft tube running the length of the zipper, a thick and cushy draft collar, and a hood with an adjustable cinch. While some hoods can adjust in 2 different directions, around the shoulders, and around the face, the Yock only adjusts around the face. With such a plush draft collar, there isn’t really a need to cinch tighter around the shoulders. The collar plugs up any gaps or openings so cold air cannot escape.
The nylon ripstop shell fabric performed well during our test period. Big Agnes does not list the denier of the shell fabric, but it feels sturdy and durable rather than fragile, and since we used this bag for many nights during our test period and never experienced a rip or a tear, we are confident that it will withstand regular use by most customers. One feature that we do think enhances durability is the thick anti-snag patch that lines the zipper. This makes zipping and unzipping easier and it reduces the likelihood of catching the fragile lining in the zipper’s teeth, which might cause an insulation-losing hole.
All down bags are a little less durable and less water-resistant than synthetic sleeping bags, but for a down model, we think this one will perform reliably.