Minus33 Merino Wool Expedition Base Layer Crew (Men's 400gsm) Review (2026)

Who this base layer suits

Minus33 built this crew, sold under the Yukon name, as its expedition-weight top, using 400 grams per square meter of 100 percent Australian merino wool with 18.5 micron fibers. That places it firmly at the heavy end of merino base layers, intended for conditions around 0 degrees Fahrenheit and below during activity, and up to 30 degrees while inactive. For one-bag travel that narrows the audience considerably, to travelers heading somewhere genuinely cold, winter mountaineering, Arctic or subarctic trips, or extended time outdoors in deep winter, rather than general four-season travelers who just want a warm layer for occasional cold snaps. Anyone packing for a typical city trip with a few cold days will find this heavier than what the trip actually calls for.

Fabric, fit and features

The interlock knit construction uses flat lock seams to reduce chafing, a crew neckline with a tagless label, and carries a UPF 50 plus rating for sun protection when worn as an outer layer. Minus33 describes the fit as regular, with a little room to move rather than a tight base layer cut, and sizing runs from XS through 4XL with tall sizes available from medium through 3XL. A size large weighs about 17 ounces, which is meaningfully heavier than a typical 150 to 200gsm merino travel shirt, and that weight is the direct trade-off for the warmth this piece is built to deliver. Merino's natural moisture-wicking and odor-resisting properties still apply at this weight, so it functions reasonably well across a few wears between washes despite the heavier fabric.

Caring for it while traveling

Minus33 recommends machine washing this piece cold on a gentle cycle with a mild or wool-specific detergent, turning it inside out first, and tumble drying on low heat. Fabric softener and bleach are both explicitly discouraged, since they degrade wool fibers over time. For long-term storage between trips, the brand suggests an airtight container, which also helps protect against moths, a common risk for stored wool garments. On the road, the heavier fabric takes noticeably longer to air dry than a lightweight merino tee if hand washed in a sink, which is worth planning around on a trip without laundry access every few days.

Trade-offs against lighter merino picks

This guide ranks several lighter merino pieces well ahead of this expedition-weight crew for general one-bag travel, including Merino.Tech's 165gsm T-shirt and Ibex's 24-Hour Merino crew, both of which pack smaller, dry faster and suit a wider range of climates. The trade-off is warmth: none of those lighter options come close to replacing a real winter layer the way this 400gsm piece can. Western Rise's merino button-down adds versatility for travelers who want a shirt that also looks presentable, something this expedition crew, built purely as a base layer, does not attempt to do. Anyone torn between packing this piece and a synthetic fleece for a cold trip should weigh that this merino top adds odor resistance a fleece lacks, at a higher price and slower dry time.

Verdict on who should buy it

Buyers heading into genuinely cold conditions, where 0 degrees Fahrenheit or colder is a realistic daytime scenario, get real value from this crew as a dedicated warmth layer that can occasionally stand in for a fleece. For the much larger group of one-bag travelers packing for typical trips with a mix of mild and cool weather, a lighter merino top in the 150 to 200gsm range will pack smaller, dry faster and cover more of the trip's actual conditions, making this expedition-weight piece a specialist buy rather than a default choice.

Frequently asked questions