Jöttnar Uller Base Layer Review

© Toby Archer

Luxurious is, I think, the best word to describe the Jöttnar Uller.

The Uller is Jöttnar's first base layer and as with many of their other designs they haven't gone down the obvious path in selecting to use yak wool!

The Jöttnar Uller
© Toby Archer

Until being asked to review the Uller, the only things I've seen made out of yak's wool were those incredibly scratchy and itchy jumpers and wooly hats you can buy from tourist shops in Thamel, Kathmandu.

So the first thing to say is that the Uller, which is actually a synthetic/yak wool mix, is that it isn't in the slightest bit scratchy. Indeed it is the opposite: delightfully soft and warm feeling. Jöttnar claim "yak wool provides superior warmth, breathability and moisture transfer compared to merino, and delivers built in odour resistance."

I've been a big fan of merino for some years now (although I am going back to using synthetics in certain - normally very sweaty! - situations), but would say from wearing the Uller, I would agree that it seems to hold moisture less than merino but it's hard to say how much that is because of the synthetic component to the knit and how much it is the yak wool.

I've found other wool-synthetic mixes, like Rab's MeCo also hold less dampness than pure merino, so it's hard to know.

Enjoying the sunshine in the Uller - below a shady Great End.
© Toby Archer

What I love about merino is the odour resistance, and here the Uller works just as well. I've worn it for a number of weekends now, getting it plenty sweaty slogging up to winter climbs, keeping it on all day, even wearing it overnight in my sleeping bag on one occasion. But still by Sunday night it went in the laundry basket just because I knew it must be a bit grubby now, not because it smelt in the slightest. I've also found that it is easy and un-fussy to wash, it can just be chucked in at 40 with everything else. This results in a little pilling but nothing I wouldn't expect. It also keeps its shape after washing much better than pure merino does - probably again down to the synthetic component of the fabric.

The design is great: soft flat seams; a deep chest zip for those sweaty walk-ins and even a little pocket for your car key or iPod. It is nice and long, easily staying tucked in when climbing.

I found the sizing quite generous - I'm a medium for most items and the Uller is fine in medium, but I like snug base layers and had I been in shop to try it, I would have even tried on a small to see how that was.

The knit is reasonably thick, hence the Uller is really warm and cosy, probably meaning for most people it won't suit them for summer use. It really comes into its own in the cold, although I've worn it lots for cold days out rock climbing in winter, not just for snow and ice.

The Uller, below various other Jöttnar layers, high above a frozen Sprinkling Tarn.
© Toby Archer

Which leaves just one issue - the price! The Uller sells for £90, way more than I have ever spent on a base layer; in fact probably three times what I've ever spent on one.

Without a doubt, the Uller is a better baselayer than a cheapy synthetic you can get from Decathlon for a tenner. But is it nine times better? You can probably wear it for much more than nine times longer without it getting stinky, so if you are off somewhere remote with no washing facilities, yet don't want to be the smelliest person in the tent, then it might be worth considering.

At the moment (I'm doing teacher training, so both not earning an income and paying university fees!) I couldn't justify the cost; but everyone's situation is different and some people are happy and able to spend more on equipment that is of top quality and does its job well, indeed does it with some panache!


If you can afford a bit of luxury in your life, but still want a top quality base layer for all things cold and serious in the winter mountains, the Uller is well worth considering.

Jottnar Uller What Jottnar Say:

A high performance yak wool blended base layer for use in cold conditions. Yak wool provides superior warmth, breathability and moisture transfer compared to merino, and delivers built in odour resistance.

Combining the excellent temperature regulating properties of yak wool with the shape holding and durability of synthetic fibres, creates an exceptional base layer truly worthy of its place in the Jöttnar line up. It's soft to the touch, stretchy and luxurious to wear. Flatlocked seams, stand up soft collar and quarter-venting chest zip further aid comfort and versatility.

When in the mountains, why be sheep when you can be a yak?

For more information visit Jottnar Website

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