Down and Insulated Jackets

Mountain Equipment Oreus Jacket | Review

This award-winning new jacket from Mountain Equipment has some excellent eco creds and an innovative fabric that brings a host of virtues to the table

Mountain Equipment picked up a prestigious ISPO Award for this jacket upon its release at the start of 2024, with the jury praising it for its “innovative new development of synthetic insulation’ and its “particularly good warmth-to-weight ratio”. Perhaps the standout aspect of it is the new Aetherm insulation that Mountain Equipment have developed, this being the first product it has been paired with.

What the Mountain Equipment Oreus Jacket is Best Suited to?

This is a warm and light synthetic insulated jacket that suits alpine mountaineering and winter hillwalking. It’s the kind of layer that will keep you warm when moving in the hills but it’s a little light for any activities that might have you standing around for long periods in very cold conditions – whether that’s while belaying or standing behind a tripod waiting for sunrise.

The Fit

I tried this in a medium, my usual size, and the fit was perfect. I’m 5 foot 10 and have an average build. I found that there was enough room to wear a thick fleece underneath and it paired well with a waterproof jacket worn over the top of it too.

The arms have good articulation. I found I could reach up high in it without the hem lifting. I also found that I could comfortably use the hand warmer pockets while wearing a backpack with a hipbelt – it should be possible with a climbing harness too.

Construction

The Oreus is made from 100% recycled shell and liner materials and there’s a 100% recycled fill too. The outer material has a very thin feel to it, so you’ll want to treat it with a bit of care when around sharp stuff. Still, I found it was able to stand up to the straps of a heavily loaded backpack and also to some abrasion on rough rock.

The insulation is a newly developed material by Mountain Equipment called Aetherm. It involves tiny insulating polyester fibres that are interlocked with a layer of film that radiates your body heat back to you. Wearing the jacket, the insulation seems to stay in place nicely so there are no cold spots. It feels lofty too, though not quite as lofty as down. Wearing the Oreus in wet weather, I found the DWR (which is PFAS free) held out for a bit before giving in to saturation. Once saturated, the insulation lost most of its loft but it did still provide a good degree of insulation – that’s the beauty of synthetic fill compared to down.

OM editor Will testing the Mountain Equipment Oreus in the Lake District. Will is 5 foot 10 and wearing a size M. Photos: Dave Macfarlane

The fill is also very compressible – it feels a lot like down in that regard. The whole jacket can quickly be packed away into its own internal dump pocket, forming a small bundle about the size of a Nalgene bottle. I found that the fill quickly retains its loftiness once it’s been shaken out a bit.

Details

The Oreus has an adjustable hood with cords across the rim and a Velcro tab at the back. It can be worn both underneath or over a helmet. I like the fact that the hem adjustment tabs have unlooped ends. These reduce the risk of the cord getting caught on equipment, branches, or other outdoor elements, which is especially important during activities like skiing, hiking, or climbing.

The two handwarmer pockets are very large – big enough to fit an OS map inside them. There’s also a useful chest pocket which is the right size for a smartphone. In cold conditions I preferred to keep my phone on the inside of the jacket as the external one has a thin face fabric meaning the battery is likely to drain away quickly.

I like the fact that this has a press stud at the base of the main zip and a two-way zip. This allows for easy venting while maintaining secure closure and warmth at the core. There’s also an internal storm flap that blocks out draughts well.

Verdict

There are good sustainability efforts here and the right technical details that you’d want from a jacket for cold weather activities. I think the synthetic fill is impressive too. It feels a lot like down and makes for a jacket that’s warmer than you’d expect given the low overall weight and bulk.

The Competition

Other similar jackets to consider include the Arc’teryx Nuclei FL which is a bit lighter but more expensive and the Rab Generator Alpine which is warmer but also heavier. The Patagonia Micro Puff is similar in warmth and price.