How to Wash Alpaca

The Chemistry

Alpaca fibre comes from the fleece of alpacas, a camelid native to the Andean highlands. Two alpaca breeds produce commercially significant fibre: Huacaya alpaca (accounting for approximately 90% of production) produces a dense, fluffy, crimped fibre that resembles fine merino; Suri alpaca produces long, lustrous, low-crimp fibre with a silky drape more similar to mohair. The two types differ in both appearance and wash behaviour. The most structurally distinctive feature of alpaca fibre — compared to sheep's wool — is medullation. Many alpaca fibres have a hollow central channel running through the core of the fibre, called the medulla. This medullated hollow structure is what gives alpaca garments their exceptional warmth-to-weight ratio: the hollow core traps a column of still air along the length of each fibre, providing significant insulation from trapped air rather than from fibre mass alone. The same mechanism operates in polar bear guard hairs (which are hollow) and in the hollow structure of geese down (which traps air in three-dimensional clusters). The hollow fibre also means alpaca feels lighter and less dense than wool of equivalent warmth. Scale structure is the second critical structural difference. Alpaca fibres do have a scale structure — overlapping protein scales along the fibre's length — but these scales are less prominent and less sharply defined than the scales in sheep's wool. Specifically, the scale protrusion (the height of the scale edge relative to the fibre body) is smaller in alpaca than in merino, and the scale edges are less sharp. In wool, these prominent scales are what drive felting under heat and agitation: when scales interlock with adjacent fibre scales under mechanical agitation, the scales act as one-way ratchets — fibres can only move in one direction relative to each other, and the resulting progressive fibre migration leads to irreversible compaction and matting. Alpaca's less prominent scales produce the same interlocking mechanism, but require more energy (more agitation, higher heat, or both) to initiate it. This gives alpaca a slightly wider safety margin than fine merino before felting occurs — but it does not make alpaca felt-proof. Alpaca will felt under machine wash conditions; it just takes more aggressive conditions than merino. The third major structural difference from wool is the absence of lanolin. Wool fibres naturally contain significant amounts of lanolin, a complex wax mixture secreted by sebaceous glands in sheep. Lanolin is the primary reason some people have skin reactions to wool — they are reacting to lanolin rather than the fibre protein itself. Alpaca fibres contain no lanolin, which is why alpaca is often described as hypoallergenic (though a small number of people do react to the alpaca fibre protein itself, the lanolin allergy trigger is absent). The absence of lanolin has a practical washing consequence: alpaca does not have the waxy, slightly water-resistant surface character of untreated wool. This means alpaca gets wet more readily than equivalent wool and saturates more quickly. Enzyme detergent is destructive to alpaca for the same reason as with all protein fibres. Protease enzymes in biological detergent are specifically designed to break down protein chains — they cannot distinguish between food protein stains (what they are intended to digest) and alpaca fibre protein (keratin). Repeated washing with enzyme detergent progressively breaks down the alpaca fibre, causing thinning, loss of surface lustre, and increasing fragility over time. Suri alpaca deserves separate mention. The long, low-crimp Suri fibre is more silky and lustrous than Huacaya, but also more vulnerable to shape distortion when wet. The low-crimp nature of Suri fibres means the knit structure made from them has less natural elastic recovery — once stretched wet, Suri alpaca takes longer to return to its original dimensions. Suri garments should be laid flat to dry with even more care than Huacaya, and should be laid on a flat surface rather than a towel (which can create imprinted texture marks on the glossy surface). The comparison to cashmere is worth making. Cashmere comes from the undercoat of cashmere goats and is also a protein fibre with a scale structure. Cashmere scales are generally more prominent than alpaca scales — cashmere felts more readily than alpaca under equivalent conditions. Both are lanolin-free in their cashmere and qiviut forms. Both require enzyme-free detergent, cold water, and gentle handling. Alpaca's slight additional resistance to felting comes at the cost of less of the extreme softness for which cashmere is valued — the softest cashmere (sub-14 micron, Grade A) is perceptibly softer than equivalent alpaca.