When outfitting yourself for winter apparel, it's easy to place the focus on outerwear; the waterproofness, the breathability, the style and colour. All important considerations for sure, but winter comfort on the mountain is first about being warm. That warmth radiates from your own skin and needs to be contained there effectively, which is why base layers, often called “thermals,” are the first thing you pull from your drawer when getting dressed for your winter day in the outdoors. If you are still dressing under your jacket with cotton t-shirts and hoodies, then it's time to upgrade.
Merino wool has been touted as the saviour of winter base layers, largely due the global success of New Zealand company Icebreaker, which first started peddling merino garments in 1994. Icebreaker's clever marketing strategies, with slogans such as “Think, don't stink” have resonated with the market. Icebreaker is now available in over 3,000 stores in 44 countries, with an annual turnover of $180 million. That's a lot of merino sheep to clip.
Most people are aware of the advantages of merino; it's incredibly warm for how much it weighs, it breathes and wicks sweat pretty well and, best of all, it doesn't stink even after weeks of wear.
On the flipside it's very expensive, considerably more fragile than it looks and, once wet from perspiration, takes considerably longer to dry than synthetics.
Polypropylene has been the mainstay of synthetic base layers for decades, though many brands now use a blend with polyester in order to give garments a softer feel and added warmth. It was a welcome change from cotton undergarments back in the day, but the smooth fibres of “polypro” are a breeding ground for odorous bacteria — hence the need to wash the garment after every use. In recent years, treatment methods involving recycled silver has helped combat synthetic stink, but it will never come close to the natural anti-odour properties of wool. The fine, scaly fibres of merino wool do not encourage smelly bacterial growth, hence the “nature's miracle” prophecy so often told by sales reps.
I own dozens of merino wool garments from head to toe, a luxury afforded to me from working in retail for several years. But the more I’ve worn merino the more I’ve come to understand its shortcomings.
The biggest thing is the how fragile the weave is. I've torn gaping holes in merino long johns just from putting them on in a hurry and turned a $130 jersey into a rag after a bike crash into some bushes. Pick holes will form after consistent wear, and those holes slowly grow into tears, particularly in the lighter weight fabrics. And as temperature regulating as merino can be, once you sweat in it you'll remain wet for a long time. It's a far cry from the perpetually damp cotton t-shirt, but if you are doing constant aerobic exercise, such as nordic skiing or ski touring, quality synthetics are the way to go.
I'll generally wear merino while I'm skiing in the resort because it keeps me warm on the chairlift and handles the short bursts of body activity — without me overheating — while I'm skiing down. In the backcountry, when I'm slogging uphill for several hours at a time, the moisture management of synthetics is my saving grace. Having the choice between the two will keep you as warm, dry and comfortable as possible in the mountains this winter.
Vince Shuley is a Whistler-based freelance writer with an outdoor obsession. If you have any questions or suggestions for this column he can be contacted at firstname.lastname@example.org.