Icebreaker Merino Wool Base Layer: Product Review

Icebreaker Base Layer

Disclosure: Got these base layers free from Icebreaker for the purpose of this review. All opinions are my own.

My History With Icebreaker And Merino

I always thought of wool as being itchy and uncomfortable.

Wool may be a natural, sustainable, and practical material for clothing, but as a lover of soft and comfy, itchy and uncomfortable clothes won’t fly with me even for a miracle material.

Then a hiking guide in New Zealand introduced me to Icebreaker.

Icebreaker is a New Zealand based company that makes active-wear and performance wear from fine merino wool.

My mind was blown.

All the benefits of wool without being itchy?

I now have many Icebreaker items.

A base layer (my first Icebreaker purchase in New Zealand, now 11 years old and still going strong), a camisole, a few lightweight tops I wear for running, a multi-style top that is the first thing I pack for every trip (the Bliss Wrap – LOVE), and a dress that is my summer post-run change into outfit (the Yanni Dress).



I try to support responsible companies whenever possible.

Icebreaker definitely qualifies.

By all accounts, they are an ethical company and take great pride in being sustainable. Their philosophy is: “We explore the relationship between people and nature. It’s about kinship, not conquering. Nature is our hero.”

They also take an active role in ensuring the welfare of the animals that supply products to them.

Some of my older Icebreaker gear came with a ‘baa-code’ a code that could be tracked online to find out more about the farm where the clothing’s wool was sourced. They don’t appear to do baa-codes anymore, but it was super fun to check out when they had it.

What’s The Deal With Merino?

Merino sheep are an ancient breed of sheep that live in the mountains. They have evolved a superfine, breathable fleece to survive in the freezing winters and the super hot summers in the mountains.

According to the Icebreaker website, merino wool:

  • Provides temperature control.
  • Is breathable. It absorbs and releases vapor to prevent claminess.
  • Provides UV protection. Merino gives you extra (natural) protection against the sun’s harmful rays
  • Is naturally anti-bacterial. It can be worn for days without washing without any stink. I won’t pretend to understand the science of this, but I can attest to it. I always pack my Icebreaker camisole when I travel and wear it nearly every day as a base layer – it rarely needs washing.

Base Layers

A base layer is exactly what it sounds like, a layer of clothing designed to wear right against your skin. It provides warmth and wicks sweat away from your skin.

A base layer is the first step in the layering process.

I admittedly don’t have a huge need for base layers in the Bay Area, although I do break them out regularly for volunteer shifts at races. These shifts often start super early and can be super cold.

Icebreaker sent me a full bast layer outfit – a Bodyfitzone 150 Zone Long Sleeve Crew and a Bodyfitzone 150 Zone Leggings.


Icebreaker merino wool base layer
The base layers I tested out

I tested out the base layers during my Thanksgiving Turkey Trot volunteer shift and on a trip to visit family in Minnesota (where I most definitely needed the extra warmth when the highs were only in the mid-teens – I’m now a California wimp and I’ve lost my ability to endure those kinds of temps without extra layers).


Fit is super important for base layers since they are worn under other clothing. Anything too bulky or awkward would get in the way.

These base layers didn’t feel bulky at all.

I wore the bottoms mostly under jeans (while not tight jeans, they were snug fitting). The jeans didn’t fit or look any different with the base layer under them.

The seams on these base layers are all sewn to ‘lay-flat’, so there is no extra bulk, even at the seams.


I for sure noticed the extra warmth when I was walking outside (with a temp around 10). While I was still cold on the walk, my legs didn’t get too chilled.

I can’t say the same for my feet (I wish I’d been wearing my Icebreaker socks!), they were freezing by the time I got home.

I’m a little baffled by merino’s temperature control properties.

While I was noticeably warmer while outside with the base layers, I didn’t notice that I was significantly more warm while indoors. Merino does that – it keeps you warm in cool weather and cool in hot weather.


Judging how well-wicking something is hard for me. I only tend to notice wicking:

  • if it’s super hot and I’m sweating up a storm, or
  • it’s done poorly.

I wore these base layers mostly for walking and so I didn’t get terribly sweaty. I wasn’t able to fully test out the wicking capabilities of these base layers.

However, I can attest to how well my other Icebreaker gear wicks sweat. I can only assume these layers will do the same.

Weight Options

Icebreaker clothing is rated based on what temps it will protect against. They have ‘weight’ options from 120 to 380 (featherweight – heavyweight). I had the 150 – ultralight. This level was perfect for my early morning volunteer shift in the Bay Area.

I could have used a few levels warmer when in Minnesota.


The downside of all of this? Cost.

Merino wool, and Icebreaker, does not come cheap. The top and the bottom I tested out retail for $90 each.

But Icebreaker is worth it.

When taken care of properly, Icebreaker gear can last decades. I still have (and often use) the first top I got from Icebreaker over a decade ago.

In Summary

I love these base layers and support Icebreaker as an ethical and responsible company. While their gear isn’t cheap, it is well worth the investment.


Icebreaker Base Layer

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