How to Wash Wool Without Shrinking

Wool shrinks when exposed to heat, agitation, and sudden temperature changes — but with the right technique, you can wash wool safely at home every time. Here's exactly how to wash wool without shrinking.

Why Wool Shrinks

Wool fibers have microscopic scales on their surface. When exposed to heat and agitation, these scales interlock and the fibers mat together — causing irreversible shrinkage. The three main causes are:

• Hot water — opens the scales and makes them prone to felting
• Agitation — causes the open scales to interlock
• Sudden temperature changes — shocks the fibers and causes felting

Avoid all three and your wool will not shrink.

Method 1: Hand Washing (Safest)

1. Fill a basin or sink with cool or lukewarm water (max 30°C / 86°F).
2. Add a small amount of wool wash detergent — about a capful. Never use regular detergent or fabric softener with enzymes.
3. Submerge the wool item and gently squeeze the water through. Do not rub, wring, or twist.
4. Soak for 10–15 minutes.
5. Drain and refill with clean cool water at the same temperature. Gently squeeze to rinse. Repeat until no soap remains.
6. Press — do not wring — excess water out gently.
7. Lay flat on a sweater drying rack and reshape to original dimensions. Air dry away from direct heat and sunlight.

Method 2: Machine Washing (When Label Allows)

Only machine wash wool labeled "machine washable" or "superwash wool."

1. Place the item in a mesh laundry bag to protect it from agitation.
2. Select the wool or delicate cycle with cold water.
3. Use a wool-specific detergent.
4. Use the lowest spin speed available.
5. Remove promptly and lay flat on a sweater drying rack to dry.

The Most Important Rules

• Always use cool water — never warm or hot.
• Never wring or twist — press water out gently.
• Never put wool in the dryer — heat causes irreversible shrinkage.
• Always lay flat to dry — hanging stretches wet wool out of shape.
• Keep water temperature consistent — don't switch between cold and warm water during rinsing.
• Use wool-specific detergent — regular detergents contain enzymes that damage wool fibers.

Frequently Asked Questions

What temperature water should I use to wash wool?

Cool to lukewarm — maximum 30°C (86°F). Cold water is safest. Never use warm or hot water, which opens the fiber scales and causes felting and shrinkage.

Can I use regular detergent on wool?

No — regular detergents contain enzymes (protease) that break down protein fibers like wool and cashmere. Always use a wool-specific detergent that is enzyme-free.

How do I dry wool without shrinking?

Lay flat on a sweater drying rack and reshape to original dimensions while damp. Never hang wet wool — it stretches. Never put in the dryer — heat causes shrinkage.

Can I wash all wool at home?

Most wool can be hand washed safely at home. Machine washable wool can go in the washing machine on a delicate cycle. "Dry clean only" wool should be taken to a professional cleaner.

How often should I wash wool?

Wool is naturally odor-resistant and doesn't need frequent washing. Wash every 3–5 wears, or when visibly soiled. Air out between wears to refresh. Over-washing shortens the life of wool garments.