The Black Diamond Hot Forge Hybrid is certainly a fusion of some big names in the insulation and material world. With a Pertex shell and Primaloft insulation put together by Black Diamond the foundation is set in the right way.

What Black Diamond Say

Down and synthetic insulations both have unique benefits in the mountains, and the Black Diamond Hot Forge Hybrid Jacket combines the two for functional warmth in ever-changing weather conditions. We used PrimaLoft® Gold Insulation Down Blend, made from 70% DWR-treated goose down and 30% PrimaLoft synthetic fibers, in the body of the jacket for warm, highly compressible performance. In more exposed areas, we used PrimaLoft Gold insulation to retain maximum warmth even when wet. The jacket packs down into an internal zip pocket with a carabiner clip loop for easy attachment to your harness on multi-pitch routes.

What My Outdoors say

The Hot forge is a thin insulation layer, I can see it best used as a mid-layer for high or cold periods. It is a nice layer to have to put under a shell whilst ice climbing, it’s not bulky and slots in between layers without any fuss.

Movement initially looked like it may be an issue as my medium felt quite neat but in practice it was fine, I had no issue with stretching and other related movement didn’t cause it to pull under the arms or feel restrictive. It is well sculpted and has an athletic fit. There isn’t any noticeable stretch in the shell of the jacket but it may be because of the light 20 denier material.

There is a selection of pockets, two hand warmers, an inside mesh pocket and two inside behind the hand warmers perfect for stashing gloves.

The Pertex Quantum as I said is light, it does have reasonable water repellencey for its thickness but it isn’t long until it’ll let through to the insulation. It is however very windproof, surprisingly so. When walking back from a days climbing in the Cairngorm I had it on under my shell. When I descended I was getting a bit warm for the layers I had on, so the eternal question: Do I ride it out or take my insulation off from under my shell? There was a fair bit of wind, ice cold at that, so I was apprehensive to take away the wind cheater. However, in the name of science I dropped my pack and reluctantly took off my shell, expecting to be cut in half by the wind. To my surprise there was very little affect from the wind and I wandered on quite happy back to the car fending off the blustery descent. The baffle behind the main zip is made of stern stuff so no leakage of cold wind there.

The Quantum material being so light does have a risk of wear, I have noticed a couple of areas in the material where it has been pulled. It hasn’t had a great deal of rough treatment, a couple of evenings on the crag but normally just pack wear that would cause it. Having such a light material will have its trade-offs.

The insulation is an interesting mixture of Primaloft. Across the shoulders is fully synthetic Gold insulation, which has a high warmth to weight ratio. It’s in a good place as this is obviously the area that is exposed from the sky above, also good for pack straps not damaging any down through restriction.

The body where the jacket is ribbed contains another form of hybrid, this has Primaloft Gold Insulation Down blend. The feathers that make up 70% of the content are hydrophobic and the remaining 30% is ultrafine synthetic fibres. The theory is it becomes light, water repellent and packable. I think it ticks those boxes well. This is achieved overall by the combination of the light outer material.

One thing I did notice through use was the outer allowed through a reasonable amount of insulation “fuzz”, on the inside of fabric jacket (as opposed to a hardshell) I found that there was a white spray of insulation stuck to the inside. I’m used to losing some feathers through the outer but it was more like the shell was too thin and let out a lot of fine insulation out. It may be that the Primaloft Blend is finespun meaning it could need a higher denier material to keep it in check. I’m not going to tear open to find though. It has now done all its shedding now though, so I am left with the level of insulation I will get.

The Hot Forge folds in to the mesh inside pocket which packs it down quite nicely, ticking the packable box I mentioned before. And a nice little loop to stick a carabiner on to keep on your harness.

Initially when the Hot Forge arrived I thought the lack of hood would be its downfall, but what it has made me realise that there are times when you can have too many hoods: hardshell, softshell, insulation and sometimes baselayer. All these together can make your neck pretty bulky and can cause a bit strangulation if not kept in check. Or those four layers can push down on your climbing helmet causing some discomfort.

So, the Hot Forge not having a hood starts to make more sense. Likely a beanie will be the initial skull covering anyway so dropping a hood layer is good. There is a hooded version if you can’t get your head round it!

The cuffs are a small feature but interesting, there is a larger elastic part on the underside. I haven’t figured out the reason for it, apart from it oddly works. It’s comfortable and flexible so I’m in to it.

Overall, the Hot Forge is a fantastic fusion of technologies. It has dexterity and it keeps you warm, possibly there are some lighter comparable products however the insulation is well placed. It keeps the core warm with the mix of hydro down and the fully synthetic on the shoulders and arms gives enough protection and insulation to keep you going. Black Diamond have done well with the Hot Forge, it is a truly functional and well combined hybrid.