The Right Way to Wash Wool, Linen, and Cotton

The labels on most clothes give general guidance but rarely explain the reasoning. “Wool: cool wash, lay flat to dry.” Why? “Linen: hot wash if you must, line dry.” Why? “Cotton: practically anything.” Why?

Understanding why each natural fibre wants what it wants makes the right care choices obvious and removes the guesswork. The fibres have different structures, different responses to water and heat, and different vulnerabilities. Treat each according to its nature and your wool stays the right shape, your linen ages beautifully, and your cotton outlasts your patience for it.

Wool: the most vulnerable, the most rewarding

Wool is a protein fibre with a complex scale-covered surface. When wet and agitated, the scales open up and interlock with neighbouring fibres. This interlocking is the basis of felting, and it is essentially irreversible. A wool jumper that has been felted is permanently smaller and denser than before.

The rules for wool:

• Wash in cool water (under 30 degrees, ideally even cooler)
• Use a wool-specific detergent (Persil Wool Mix, Ecover Delicate, or any “wool & silk” formulation). These have lower pH and gentler surfactants.
• Minimise agitation. A wool cycle on your washing machine, or hand-washing with very gentle movement, is ideal. Avoid the “extra rinse” and “spin” options on the most aggressive settings.
• Do not transfer directly from hot to cold or vice versa. The temperature shock can also cause shrinkage.
• Squeeze, do not wring. Twisting wool fibres while wet damages them.
• Lay flat to dry on a clean towel. Reshape gently while damp. Never hang wet wool, which stretches under its own weight.

For very valuable wool items (cashmere, fine merino), hand wash in lukewarm water with a small amount of wool detergent, soak for 10-15 minutes, gently squeeze out the soapy water, rinse in clean lukewarm water until clear, squeeze out excess water against the side of the sink (do not wring), roll in a clean towel to absorb more water, then lay flat to dry.

The patience matters. A wool jumper treated carefully looks better at year five than a similar jumper roughly washed looks at year one.

Linen: more forgiving than you think

Linen is made from flax fibres, which are tough, strong, and remarkably absorbent. Unlike wool, linen does not felt or shrink dramatically. It can take more aggressive washing than wool without harm.

The rules for linen:

• Wash in warm (40 degrees) or even hot water if needed. Hot water gradually softens linen, making it more pleasant against the skin.
• Use any normal detergent. Linen is not picky.
• Standard washing machine cycles are fine. Linen tolerates agitation well.
• Expect significant wrinkling. This is normal for linen and part of its charm.
• Tumble drying is fine on low or medium heat for everyday linen. Removing slightly damp keeps wrinkling more manageable.
• Iron while still slightly damp for crisp results. Linen takes a sharp crease beautifully.

The single thing to know about linen: it gets better with age. New linen is often stiff and crisp; well-worn and washed linen becomes soft, drapes beautifully, and develops a quality of finish that synthetic fabrics cannot match. Do not be afraid of washing linen; embrace it.

The exception: structured linen garments (linen suits, structured dresses) may need professional care to preserve their shape. For these, follow the label.

Cotton: the workhorse

Cotton is the most common natural fibre in domestic clothing for good reason. It is strong, absorbent, takes dye well, washes easily, and tolerates most conditions.

The rules for cotton:

• Wash in cool to warm water (30-40 degrees) for most everyday cotton. Use hot water (60 degrees) for towels, bed linens, and items that need disinfecting.
• Most detergents are fine. Heavily soiled cotton benefits from enzyme-rich detergents.
• Tumble drying is acceptable but accelerates wear. Air drying preserves the fibres longer.
• Cotton shrinks slightly on the first wash if it was not pre-shrunk. Many modern cottons are pre-shrunk; if not, allow for slight shrinkage.
• Coloured cotton fades with hot water and harsh detergent. For coloured items, cool wash and gentle detergent extend colour life.

The main vulnerability of cotton is colour fade rather than fibre damage. The fibres themselves are remarkably durable; a quality cotton t-shirt can survive 200+ washes without significant fibre degradation. What ages is the dye, the elastic content (if any), and the original finish on the fabric.

The blend complication

Many modern clothes are blends: 70% cotton 30% polyester, or 95% wool 5% elastane. The blend behaves like the most vulnerable component. A wool-elastane blend should be treated like wool, not like elastane.

The general rule for blends: care for the more delicate fibre. Wool blends need wool care. Silk-cotton blends need silk-grade care.

Some elastane-containing items (gym wear, leggings, fitted tops) are particularly demanding because elastane degrades quickly with heat. Wash these in cool water and air-dry to preserve the stretch and fit.

The colour question

Separate by colour, especially for the first few washes of new garments. New dyes can bleed onto lighter items.

For colours that you suspect might bleed (anything vibrant, especially red, deep blue, or pure black), wash separately for the first few cycles. Once the loose dye has been washed out, the item can usually be mixed with similar colours.

Cold water reduces colour bleeding compared to hot water; this is another reason to default to cold for coloured items.

The temperature rule of thumb

If in doubt about temperature, choose cool. Most clothes are cleaner than we think after a few hours of wear. The mechanical action of the washing cycle combined with enzyme detergent removes most soiling without high temperatures.

Reserve hot water for:

• Bed linens and towels (cleanliness reasons)
• Items that are genuinely heavily soiled
• Items that have been worn during illness (the heat helps reduce bacteria)

For everything else, cool or warm is plenty.

Storage considerations

After washing and drying, store fibres according to their nature:

• Wool: folded (never hung), in breathable bags, with cedar or lavender to deter moths
• Linen: hung in a wardrobe; linen drapes well from hangers and benefits from air circulation
• Cotton: hung or folded, depending on whether you want sharper or softer creases

For seasonal storage, wash all natural fibre items thoroughly before packing them away. Stored fibres with any food, sweat, or body oils still on them attract moths.

For more on the broader habits of caring for clothes, see our slow wardrobe piece. For the related question of damage during drying, see our tumble dryer damage.

For a related angle, our piece on How to Tell When a Garment Is Worth Repairing covers a closely connected problem.