Gear Review: Eigerjoch Light IN Hooded Jacket By Mammut
The Mammut Eigerjoch Light IN Hooded Jacket is a lightweight, breathable insulated layer built for alpine pursuits. With Primaloft Gold Active insulation, stretch panels, and a helmet-compatible hood, it’s perfect for big hikes, climbing, and fast-moving mountain adventures.
When you’re pushing high into the alpine or navigating fast-moving mountain missions, you need a midlayer that won’t weigh you down. The Mammut Eigerjoch Light IN Hooded Jacket is designed with exactly that in mind! Ultralight warmth, breathable synthetic insulation, and technical details that shine when the weather turns rugged.
This isn’t your average puffy, and that becomes apparent from the moment to put it on. It’s part of Mammut’s Eiger Extreme collection, meaning it’s built for serious mountaineering, backpacking, and alpine treks. Think of it as a go-to piece when you need warmth without bulk, whether you’re layering under a hardshell or throwing it on for summit transitions.
Standout Features
- Lightweight Insulation: Mammut uses Primaloft® Gold Active for breathable warmth that won’t overheat you during high-output climbs or epic routes.
- Stretch Panels: Strategic stretch panels under the arms and along the sides allow for a full range of motion.
- Athletic Fit: Streamlined design means it layers well under shells without feeling bulky.
- Helmet-Compatible Hood: Snug and adjustable for climbing and class 3+ terrain.
- Durable Face Fabric: Pertex® Quantum Air offers wind resistance while still allowing breathability.
- Packs Small: Compresses easily in a pack, making it a reliable “just in case” layer.
Trail Tested
I put the Mammut Eigerjoch Light IN Hooded Jacket to the test on multi-day backpacking trips in the alpine, where the weather can change faster than you can lace up your shoes. The jacket quickly proved itself as a layer I reached for often; lightweight enough to throw in my pack without a second thought, but warm and protective when I needed it most.
At camp, it kept me comfortable in the crisp evening air without feeling bulky or restrictive. On trail, its Primaloft® Gold Active insulation struck a great balance between breathability and warmth, meaning I didn’t overheat during steady climbs above treeline. The athletic cut fit smoothly under my hardshell when afternoon storms rolled in, and the helmet-compatible hood was a welcome feature when the wind picked up on exposed ridgelines.
What stood out most was the versatility of the piece. This jacket transitioned seamlessly from chilly mornings to mid-day pushes to evenings spent watching the alpenglow. For alpine backpacking, where space and weight are limited, the Eigerjoch Light IN is exactly the kind of reliable insulation piece I want in my kit.
Pros and Cons
Here’s how it stacks up on trail and in the alpine:
| Pros | Cons |
|---|---|
| Ultralight warmth that’s perfect for layering | Not as warm as a full down jacket: best for active pursuits |
| Breathable insulation keeps you from overheating | Price point is on the higher end |
| Stretchy, athletic fit for climbing and ski touring | Slim cut may feel snug on broader builds |
| Helmet-compatible hood and technical alpine features |
Packing It Out
The Mammut Eigerjoch Light IN Hooded Jacket is a piece you grab when the forecast looks sketchy but your route is still a go. It’s not designed to be your warmest winter belay parka, but instead your high-output insulation layer; the jacket that lets you move fast, stay warm, and breathe easy in alpine conditions.
If you’re a backpacker, alpine hiker, or anyone who spends long days in technical terrain, this jacket is worth every ounce and every penny.
My review is independent of the supplier and reflects my own opinions. Some of the links on this page are affiliate links, which means I may receive a small commission if purchases are made through those links at no additional cost to you.
