How to Wash Wool Without Shrinking

Laundry symbols for wool: symbols you’ll see on wool labels

Wool care labels often show hand wash, do not tumble dry, dry flat, and sometimes dry clean (e.g. circle P). These laundry symbols for wool help you avoid shrinking and felting.

Cold water only

The single most important rule for washing wool is temperature. Wool fibres are covered in tiny scales (like roof shingles). When exposed to heat and agitation, these scales lock together permanently—a process called felting. Once felted, wool cannot be restored.

• Maximum 30°C (86°F): Use cold or lukewarm water only. If the care label shows a hand wash symbol or a 30°C wash, follow it exactly.
• Avoid sudden temperature changes: Don't move wool from cold water to hot, or vice versa. Thermal shock can cause shrinkage even without high heat.
• Test the water: If it feels more than lukewarm to the touch, it's too hot for wool.

Hand wash vs machine wool cycle

When the label shows a hand wash symbol, hand washing is the safest option. Some wool garments are labelled machine-washable on a wool or delicates cycle—if so, you can use the machine, but follow these rules:

Do not wring: Twisting wool while wet damages the fibres and causes permanent distortion. When the label shows a do not wring symbol, take it seriously—press water out gently instead.

Drying flat

Never tumble dry wool. The heat and tumbling action will felt and shrink it. If the label shows a do not tumble dry symbol, air drying is the only safe method.

• Lay flat on a clean towel: Roll the garment in a towel to absorb excess water, then lay it flat on a dry towel or mesh drying rack.
• Reshape while damp: Gently stretch and shape the garment to its original dimensions before it dries. Once dry, wool holds its shape.
• Keep away from direct heat: Don't dry near radiators, in direct sunlight, or with a hairdryer. Even indirect heat can cause shrinkage or yellowing.
• Never hang wool: Wet wool is heavy and will stretch out of shape if hung. Always dry flat.

Why wool shrinks

Understanding why wool shrinks helps you avoid it. Wool fibres have a scaly surface (the cuticle). Under normal conditions the scales lie flat. When exposed to:

• Heat: The scales open and become more likely to interlock.
• Agitation: Movement causes the open scales to catch on each other and lock together.
• Alkaline detergents: High-pH cleaners swell the fibres and open the scales further.

Once the scales lock (felting), the fabric becomes denser, thicker, and smaller. This is irreversible. That's why cold water, gentle handling, and wool-safe (neutral pH) detergent are essential.

Superwash wool: Some wool is treated to prevent felting (superwash). These items are more forgiving and may be machine-washable—check the care label. But even superwash can shrink if dried with high heat.

Symbols for wool care

Wool care labels typically show a small set of symbols. The ones you'll see most are:

If the care label shows a dry clean symbol without any wash symbol, it's safest to take the item to a professional. Some structured wool garments (suits, coats) should always be dry cleaned to preserve shape and finish.