Why Most Merino Doesn’t Work the Way People Expect (and What Real American Wool Still Does)
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Roughly 95% or more of the Merino that ends up in apparel comes from outside the United States—primarily Australia, with China being the dominant processor (~90%). U.S. wool production overall is a tiny fraction of global output (on the order of 1% or less of total wool, and an even smaller share of fine Merino). The fiber that reaches most clothing racks has usually traveled a long way and been processed for convenience.
The most common processing step is superwash treatment (typically a chlorine-based process followed by a polymer resin coating). The goal is machine-washability: the scales on the fiber are modified or covered so they don’t lock together and felt under heat and agitation. That treatment also removes or alters the natural outer lipid layer (18-methyleicosanoic acid) that helps untreated wool shed liquid water and dirt. The result is a fiber that is easier to throw in the washing machine, but whose surface behavior is changed.
In practice, many people notice the difference. Untreated (non-superwash) wool more often beads liquid spills so they roll or blot off, holds less surface dirt, and resists building odor even after weeks of repeated wears without washing. Superwash versions are smoother and more convenient for frequent laundering, but they tend to behave more like other treated synthetic fibers once the natural surface properties are modified. The core moisture-vapor management and temperature regulation of Merino somewhat remain, yet the “spill it, wipe it, wear it again” practicality that older wool garments were known for is reduced.
This is not a claim that every superwash garment is bad. It is a description of a trade-off. Most commercial Merino is processed so it will survive modern laundry habits. The smaller amount of non-superwash American Merino that still exists retains more of the fiber’s original surface characteristics—water beading, dirt resistance, and the ability to be worn multiple days with only spot cleaning - excellent temperature regulation.
At Fern Hall we work with and wear the version that hasn’t been chemically stripped and coated for machine washing. It is the fiber that still does what wool has done for everyday use since the beginning of human civilization: handle real conditions with minimal intervention, zero plastic, and no daily wash cycle. That is a deliberate choice, not nostalgia. The majority of the market has optimized for convenience. The untreated fiber still optimizes for performance that doesn’t require constant laundering.
If you have only worn the machine-washable version, the everyday behavior of natural non-superwash wool can feel surprisingly different. Spills often roll. Odor builds slowly. A sweater can stay in rotation for weeks with only spot care. That is the fiber working closer to its original design.