Meriwool Merino 250 Base Layer Bottom Review

Overview

The Meriwool Merino 250 Base Layer Bottom is a pair of full-length thermal leggings knit from 100% merino in a 250 g/m² interlock. It’s aimed at cold-weather hikers, campers and skiers who want the warmth of a Smartwool Classic Thermal without Smartwool money. The trade-off is straightforward: plenty of warmth and a low price, in exchange for plainer construction and middling durability.

Key Specs

Spec	Detail
Weight	224 g (7.9 oz)
Material	100% merino wool
Fabric weight	250 g/m²
Knit	Interlock
Fiber diameter	18.5 micron
Category	Midweight/heavyweight thermal base layer bottom
Price	Listed at $59.99 in 2024 roundups

Performance

Warmth. This is the bottom’s strongest suit. Outdoor Gear Lab’s testers, who evaluated the men’s version, scored it 8.0 out of 10 for warmth, the highest mark in its scorecard, and described the plush 250 g/m² fabric and snug fit as the source of that. Owners echo it: reviewers describe the men’s bottoms as a go-to for winter weather, and one buyer called them soft and warm without being skin-tight. In Greenbelly’s merino roundup, the Meriwool 250 set was classed as midweight. At 250 g/m², most of the industry would call it the heavy end of merino, which matches what the leggings do best: cold mornings, static camp time and sleeping.

Breathability and drying. Here the numbers cool off. Outdoor Gear Lab gave the bottom 6.0 for breathability and 6.0 for drying speed, which puts it mid-pack among long underwear. That’s what a dense interlock does. Merino can hold a fair amount of moisture before it feels wet, but it takes a while to give that moisture back. On a sweaty climb in the mid-30s, the leggings will keep insulating, but they’ll also keep what you put into them. For high-output winter days, a lighter 150-weight bottom breathes better.

Comfort and fit. The 18.5-micron wool is on the fine side for a budget thermal. Outdoor Gear Lab’s reviewers still reported the fabric starts off slightly itchy before it settles, and noted that the simplified construction may not feel as refined as pricier rivals. Owners on retail listings paint a kinder picture: the wool isn’t itchy, sizing runs true, the waistband elastic is soft, and the cut sits close enough to wear under jeans or pants without bunching. The fit is snug rather than compressive. Since these are the women’s cut, expect a closer fit through hip and thigh than the unisex-leaning cuts from some competitors.

Durability. Outdoor Gear Lab scored durability at 6.0 and listed merino’s inherent delicacy as a drawback. That’s the standard cost of 100% merino with no nylon in the yarn: knees, seat and the inside of the thigh are where pilling and thin spots show up first. Owners who have kept their pairs going recommend cool water, a wool-safe detergent, no fabric softener and air drying. Treat them that way and they’ll last. Throw them in a hot dryer and they won’t.

Odor. Merino’s main selling point holds here as with any all-wool garment. The leggings can go a long stretch between washes, a real advantage on multi-day winter trips.

Weight. At 224 g, the bottoms are not an ultralight piece in the strict sense. They’re about what a 250-weight legging should weigh, and Greenbelly clocked the matching top and bottom set at 17.91 oz combined. Thru-hikers counting every ounce will look to 150-weight or synthetic grid-fleece options for daytime wear. As a dedicated sleep layer, 224 g is easier to justify, since it often replaces a heavier insulated bottom.

Pros & Cons

Pros

• Real warmth from 250 g/m² interlock; the top-scoring category in Outdoor Gear Lab’s testing
• Priced well below Smartwool’s equivalent, which Outdoor Gear Lab suggests as the budget alternative
• 100% merino, so it resists odor over multi-day use
• Fine 18.5-micron fiber; owners report it isn’t itchy
• Soft waistband and true-to-size fit reported by buyers

Cons

• Breathability and drying speed are only middling (6.0 each in Outdoor Gear Lab’s scoring)
• Can feel slightly itchy at first
• Durability is average; pure merino is delicate and needs gentle care
• 224 g is heavy for three-season ultralight kits
• Simpler construction than premium competitors

Who Should Buy This

Cold-season backpackers, winter campers, hunters, skiers and anyone shopping for a sleep-system bottom will get the most from these. They’re also a sensible first merino purchase for someone who wants to find out whether wool suits them before spending $100 or more. Ultralight hikers who want a single bottom for three-season mileage, high-output winter athletes who sweat heavily, and anyone planning rough use against granite and brush should look elsewhere, probably to a 150-weight merino blend or a synthetic option.

Verdict

The Meriwool Merino 250 Bottom does what a cold-weather base layer should: it’s warm, soft enough, and cheap enough that a pair doesn’t hurt to replace. It isn’t the lightest, most breathable or most durable choice, so buy it as a winter and camp layer rather than an all-purpose one. For that job, it earns a clear recommendation.