Review: Mammut Taiss Mountaineering Boots

The Taiss Light Mid GTX is a new lightweight mountaineering boot from Mammut which debuted this spring. While the colors may be understated, at least for the 2019 version, this boot is anything but. Exceptionally lightweight but still quite stiff and very dexterous, it walks well and climbs even better. I actually feel faster and lighter just putting these sick new boots on! Definitely one of my favorite boots of the summer and my new go-to for almost any type of summer alpine climbing, scrambling or mountaineering adventure.

Testing out the Taiss boots on a cold day in the Canadian Rockies.


  • Weight: 595g (Size 42⅔ or 9.5 US)
  • Last: Mountaineering Tech
  • Upper: Microfiber Race, Schoeller, Ripstop Textile and Mesh Protection
  • Lining: GORE-TEX Performance Comfort
  • Midsole: Polyurethane
  • Outsole: Vibram® Ascension Litebase
  • Construction: Board Lasted
  • Crampon Compatibility: Hybrid or Semi-Automatic
  • Lacing: Dual Zone
  • Versions: Men’s and Women’s
  • MSRP: $399 USD
  • Color: Currently black (men’s), and white (women’s), but expect more colors for 2020.
Color options: Black (Men’s, 2019), Orange (Men’s 2020) & Pink (Women’s 2020). Missing: White (Women’s 2019).

Fit and Feel:

Mammut Taiss Light Mid GTX
The Taiss boots fit more like a running shoe than a mountaineering boot, despite being quite stiff.

I sized my Taiss boots a little on the snug side for a more performance fit, as they are a performance boot. This usually means that my medium-width feet suffer for a few days while the boots relax a bit and make room. I didn’t find that this was the case with the Taiss, as the Schoeller fabric and Ripstop Textile give the toe box a forgiving feel. The boots are also shaped using what Mammut calls Georganic 3D tech. Basically it means that they spent a bunch of time mapping feet and designed a boot that really matches that shape. The result is a stiff and functional mountaineering boot that fits more like a running shoe. The Georganic 3D tech is also quite noticeable in the heel, which fits better than any other boot I have. And I have a lot of boots.

One-side-open, wrap-around type tongue design works fairly well though it did bunch up a bit when I really tightened the boots up for technical climbing.
A small gaiter-like cuff helps keep snow and gravel out of the boot.

The tongue design on the Taiss is a bit different, with the upper part of the boot wrapping around to become the tongue with no obvious variance in material or design. The outside edge of this upper tongue is left open to allow the boots to be put on. The lower tongue is stitched on both sides and is made of a lightly padded Schoeler material, for a soft and forgiving feel. When the boots are laced up loosely for an approach this tongue design works great, but it can be a bit of pain when you tighten the uppers for climbing.

The Taiss boots feature a fairly standard dual-zone lacing system with low profile fabric eyes on the lower boot and open hooks on the top. This system works fairly well though the lace tension does seem to equalize over time.


Mammut really found the Goldilocks zone when it comes to performance! The Taiss boots are quite stiff but not bulky, making them quite adept at climbing rock, snow and ice. They are the best all-round climbing boot I own. And while a boot that climbs well usually feels a little clunky when walking, the shape of the sole combined with the soft upper allows the Taiss to walk quite well on-trail.

The toe and heel of the Mammut Taiss is rockered to allow the stiff boot to walk well on-trail.

As they don’t have a ton of insulation the Taiss boots are really summer specific alpine boots. However, unlike most other summer specific boots, they’ll still tackle an amazing amount of soggy glacier walking before succumbing and allowing my feet to get wet and cold.


Unfortunately the pair I was testing suffered an early demise when someone trying to be helpful placed them too close to a fire when drying out. A very sad day! Before that terrible incident the boots were on track for a nice long life. The fabric on the uppers is a little soft and won’t take a ton of punishment, but the full, wrap-around rand helps to protect it. Excessive scree bashing would likely cause the material to wear a little prematurely though. Leather boots are ideal for that type of service.

The Vibram rubber sole on the Taiss stood up fairly well, only showing wear along toe from climbing. I did avoid kicking steps in dirt and scree though as that’s usually a death sentence for sticky rubber soles.


Pros: Exceptionally lightweight, comfortable, dexterous and versatile.

Cons: Wrap-around upper tongue can sit a bit strangely when the boots are tied tight for climbing.

Overall: Fits like a running shoe, climbs like a dream and makes me feel fast! Definitely my go-to for summer alpine climbing missions (yes, I replaced the pair that died young despite having a plethora of other boots available)!

Black Sheep Adventure Sports was provided with a sample pair of boots for testing but of course this didn’t influence us in any way.