Mammut Eiger Extreme and Light jackets

Mammut Eiger Extreme and Light Jackets

Two Mammut jackets for two different activities. Which one should you choose, for what – and why?

First there came Mammut’s Eiger Extreme collection, including the Eigerjoch for men and the Biwak for women. Then the outdoor clothing brand followed up this season with the “light” versions, the Eigerjoch Light for men and the Biwak Light for women.

Let’s start with the 800-fill down Extreme jackets. These are meant for adventures and expeditions in low temperatures. Unlike previous versions of superwarm down-fill jackets, The Mammut Extreme jackets are not styled as per the Michelin Man look. The jackets do offer great warmth but with less bulk, and they are good- looking enough to wear on the hills and, I’d say, to the local pub, too.

These down jackets have what Mammut call a double-chamber, which is also known as a V-construction and is usually seen in sleeping bags. The idea is that a zigzag of 45-degree walls stops any potential areas of cold that can be caused by through-stitching. And in each chamber, Mammut has added 800-fill down. The result is a superwarm jacket that won’t let in the cold air.

Additionally, the Eiger Extreme jackets have “fibrefill body mapping inserts”, which are aimed at drawing moisture away from the underarm area and also at the back where many people will be carrying a rucksack.

Other features include built-in wrist gaiters, which some people find does away with the need for glove liners, although this will depend on where you are walking or enjoying your adventure.

New lightweight Mammut Eigerjoch jackets

This autumn/winter Mammut  introduced their Biwak Light and Eigerjoch Light jackets. These jackets are meant to be worn as a mid or outer layer when taking part in more active, fast-moving and stop-go activities.

Mammut Eigerjoch Light Jacket

Making use of Mammut’s Polartec Alpha insulation instead of traditional down), the “light” jackets are claimed to be “extremely breathable, lightweight and very fast drying”.

(You will have seen several brands bringing out non-down insulation jackets in recent years. Down has a bad habit of becoming virtually useless when wet, so new insulation materials are now being used to offer good levels of warmth in both the dry and wet.)

Powerstretch inserts on the side and back of the Biwak Light and Eigerjoch Light jackets offer great elasticity and freedom of movement, so the jackets are perfect for climbers or fast-walking Munro baggers.

In particular, climbers will also appreciate another great detail of these jackets, the high-reach sleeves with thumb loops.

Award-winning jackets

The design and attention to detail of Mammut’s new light jackets is impressive ­ and understandably caught the attention of judges at this year’s Polartec APEX awards.  Mammut scored a win with their Biwak Light and Eigerjoch Light jackets. They were praised for style, function, workmanship, fit and the innovative use of Polartec’s new Alpha synthetic insulation.

A few words about Polartec Alpha

With so many “fill” products on the market it’s difficult to know which one to choose. Polartec Alpha is breathable, allowing sweat vapour to evaporate through the fill. The insulation still performs well when wet and dries out quickly in changeable conditions. So even if you are caught in heavy rain, a jacket filled with Polartec Alpha will quickly dry out. It is also a good wind protector and packs down into a small bundle when not in use.

I would wear the Mammut Biwak Light or Eigerjoch Light jacket as an outer layer on a cold-ish day in the hills when I plan to be moving fast and actively. Alternatively, it is a great jacket for stuffing in the rucksack and getting out at a snack stop or when belaying a climbing partner.

Stockist details: 01625 508218 or

More from Scotland Outdoors

Tags: ,


Current issue

Scotland Outdoors issue 39

Subscription plans

Upcoming Events

Jan 01

The Stoats Loony Dook

1 January, 2019 @ 10:00 am - 3:00 pm
Jan 01

New Year’s Day Dook

1 January, 2019 @ 10:30 am - 11:00 am
Jan 01

The Stoats Loony Dook

1 January, 2020 @ 10:00 am - 3:00 pm
Jan 01

New Year’s Day Dook

1 January, 2020 @ 10:30 am - 11:00 am

Get our e-news