Meriwool Merino 250 Bottom Review

Affordability may be the first thing that gets your attention when comparing the Meriwool Merino 250 Bottom to almost any other pair on the market. It's natural to be a little skeptical that Meriwool could produce a warm and comfy pair of long underwear so much cheaper than its competitors, but our tests have proven their worth — and then some. Warmth is their main strength, being almost as warm as pairs sold at nearly twice the price. Meriwool keeps the construction and design of these bottoms practical, meaning no extra panels or gusseted crotch. But you will find a front fly and strong and low-profile flatlock seams, as well as a thick and supportive waistband. You may find the superfine Merino a little itchier to start off before you wash them a few times, and overall, the fabric may not be as durable in the long run, but for an entry-level pair of bottoms, it's hard to go wrong with these.

Performance Comparison

Warmth

The Merino 250 Bottoms are toasty enough to have a fighting chance at the crown for the warmest long underwear we've tested. The midweight, 250 g/m² 100% Merino wool is as thick as we'd suggest wearing to be comfortable — unless you're going into truly arctic conditions.

These long undies are best worn when things really do get cold, as their breathability isn't as good as some of the more luxe brands. But if your idea of fun isn't joining the dawn patrol skinning up the resort slopes, and you want to stay warm during many hours of tailgating at the university's football team, these are the bottoms for you.

Breathability

Breathability for 100% Merino wool layers generally starts to suffer the warmer the layer gets. This rings true for the Merino 250 Bottom, which certainly aren't the most breathable bottoms we've tested, especially when compared to more techy pairs with built-in ventilation panels. But they stay true to their keep-it-simple ethos and let the natural thermoregulation of the wool do the talking. For most uses, the breathability found in these woolies is certainly good enough.

Where you'll run afoul is if you wear the Merino 250 for exceptionally high-output activities. Our after-work nighttime trail runs got a little uncomfortably stuffy while we power-hiked up to the summit of our favorite high point. The sweet spot for these bottoms is cold weather: they just don't perform as well when temperatures start to rise.

Comfort and Fit

The Merino 250 Bottom is made with 100% “superfine” Merino wool and is packed with plush comfort. If they initially feel slightly scratchy, give them a wash; it'll help. Low-profile flatlock seams throughout prevent chafing issues, and a 1.25" wide and soft waistband keeps these bottoms from slipping down. On the other end, tight ankle cuffs keep the legs from riding up.

We found the overall fit to be a little tighter and smaller than other brands of the same size, which is apparent when crouching down or bending a knee. The inseam measured an inch or two shorter than other size mediums we've tested, as did the waist. The seam patterns are also simpler than many other top-shelf brands: you won't find any paneling on the front or back, nor a gusseted crotch.

Generally, everything was a bit snugger, except around the front fly area, much to our relief. This means that if you're on the fence about which size to get, it's probably safe to size up. Speaking of sizes, we were delighted to see that these bottoms are available for a wide spectrum of body types and not just made for skinny athletes. Sizes range from small to XXX-Large, along with Tall lengths peppered in. Kudos to Meriwool.

Durability

Our durability scores are based both on objective lab tests and our direct observations when using the gear in the real world. Our harsh durability test makes even the toughest 100% Merino wool layers whimper, and the Merino 250 Bottom is no exception. Extended exposure to such abuse will cause rips and tears in the fabric. For base layers and long underwear, these results tell us to utilize a layer like the Meriwool exclusively underneath other layers where they'll be easily protected. Heed this warning, and the chances your purchase will last for years to come greatly improves.

The other variable you can control is when washing and drying. The manufacturer's instructions for the Merino 250 are to turn them inside out, wash them in cold water gently, and then dry them on low, on the line, or flat. These instructions should absolutely be followed to maximize lifespan. They are similar for most of the 100% Merino wool pieces we've reviewed, and most of them show similar delicate qualities. Following them, we experienced no untimely damage to the fabric, seams, or anything else that would point to less than a high-quality manufacturing process.

Drying Speed

Our lab hang-dry tests tell an often repeated story: wool fabrics tend to dry slower than synthetics, and the heavier the fabric, the slower it dries. This holds true for the heavy Merino 250 Bottom, which comes in at 7.9 ounces for a size medium. The only pairs of long underwear that dried slower were those that weighed more on our scale. This isn't a shortcoming of Meriwool as a brand — it's just physics.

What we would urge you to do when it comes to drying is follow the manufacturer's recommendation to dry only on low — or even better: hang or dry flat. The Merino 250 comes with a hang tag to help out with that. Hanging these out to dry on a late fall day in the low humidity of Colorado air had them mostly dry after an hour, with just the waistband still wet to the touch.

Layering Ability

The Merino 250 Bottom makes an excellent next-to-skin layer. Although the first wearing may feel slightly itchy from the superfine Merino wool, this should alleviate after the first wash. This soft fabric glided over most every other layer we paired it with, be it stretchy running tights, stiffer hiking pants, and jeans, or even nylon ski mountaineering pants.

Many of the design features help when these bottoms are buried underneath layers of clothes. The built-in fly can help speed up calls to nature. The soft, thick waistband works well to keep them from sagging, and the tight bottom cuffs help keep the ankles from riding up. Flatlock seams throughout minimize chafing.

Should You Buy the Meriwool Merino 250 Bottom?

The Merino 250 makes a great budget-friendly, introductory pair of 100% wool long underwear. If you want to see what all the fuss about Merino is but don't want to refinance your home to try out a pair, these are a great place to start. These long johns will definitely help keep you toasty warm whenever you need to be outside in wintry weather for hours on end. Their main weakness is in their breathability, meaning if it's too warm for these thick woolies or you're just exerting yourself too much, you may feel a little overheated. But for activities where you're staying outside in one place most of the time — think hunting and fishing — the Meriwool 250 is a perfect ally.

What Other Long Underwear Should You Consider?

Finding good quality thermal bottoms in this price range is challenging unless you look to something synthetic. The REI Co-op Midweight Bottoms are one of our favorite thermal synthetics. They won't be as warm as the Meriwool Merino 250, but synthetics, in general, are easier to wash and are much more durable than wool. Once you're ready to level up in your Merino wool game, the reigning champion for us is the Smartwool Classic Thermal Merino Bottom, but they're an investment. That said, for those extra bucks, you get a little more warmth and a bit better fit, thanks to strategic paneling.