How to Wash a Wool Blanket: Gentle Steps to Protect Yours

If you need to know how to wash a wool blanket safely, the rule is simple: prioritize hand washing in cool water (max 30°C / 86°F) using a pH-neutral, enzyme-free detergent. Gently submerge and squeeze; never scrub. If you must machine wash, use a front-loader on the 'wool' cycle. Always air dry flat to prevent shrinking.

Introduction: Safeguarding Your Cherished Wool

Wool blankets are investments. Whether it is a heavy military surplus throw, a delicate Merino heirloom, or a chunky knit, the fiber offers unmatched temperature regulation. However, caring for it intimidates most owners. You likely have a specific fear: pulling a tiny, felted, stiff mat out of the washer where your soft blanket used to be.

As a dry cleaner, I see this damage often. It is usually preventable. The "dry clean only" label is often a manufacturer's safety net, but with precise temperature control and the right chemistry, you can clean most wool at home. This guide explains the specific mechanics of wool fiber and the exact steps to clean it without destroying its structure.

The Fabric Science: Why Wool Felts

To clean wool safely, you must understand what happens at a microscopic level. Wool hair is not smooth like silk or synthetic nylon.

• The Cuticle Scale: Under a microscope, a wool fiber looks like a pinecone. It is covered in overlapping scales. When these scales are wet, they swell and open.
• The Felting Trifecta: If you combine heat, moisture, and agitation, these open scales ratchet against each other and lock permanently. This is "felting." once the fibers lock, you cannot unlock them. The fabric shrinks, thickens, and loses all elasticity.
• Protein Degradation: Wool is made of keratin, the same protein as human hair. Standard laundry detergents contain protease enzymes. These enzymes are designed to eat protein stains (like blood or egg), but they cannot distinguish between a stain and the wool fiber itself. Washing wool with standard biological detergent literally digests your blanket, leading to thinning and holes.

The Solution: You must use Cold Water (below 30°C/86°F) to keep scales flat, Low Agitation to prevent locking, and Enzyme-Free Detergent to protect the protein structure.

Pre-Wash Preparation

Before wetting the fabric, you must prepare it. Wet wool is heavy and weak; you want to handle it as little as possible once it is soaked.

1. The Shake Out: Take the blanket outside. Hold it by the reinforced hem (not the delicate weave) and shake it vigorously. You want to see dust and loose fibers fly off. This removes surface soil without water.
2. The Tape Test: Use a lint roller or sticky tape to remove pet hair. Wet pet hair weaves itself into damp wool and becomes nearly impossible to remove later.
3. Check the Label: Look for the "Woolmark" symbol. If the label says "Dry Clean Only," proceed with caution. If it says "Do Not Wash," trust it-the interior structure or lining may not withstand water.
4. Spot Test for Bleed: Dampen a white cloth with your wool wash. Dab it on an inner hem. If dye comes off on the cloth, stop. The blanket is not colorfast and requires professional dry cleaning.

Method 1: Hand Washing (The Safest Protocol)

This is the recommended method for 90% of wool blankets. It gives you total control over agitation.

What You Need:

• A bathtub or deep laundry sink.
• pH-neutral, enzyme-free wool wash (e.g., Eucalan, Soak, or Woolite Delicates).
• Thick, white terry cloth towels.

The Steps:

1. Fill: Fill the tub with cool water. Use a thermometer if possible; it must be between 20°C (68°F) and 30°C (86°F). Add the recommended dose of detergent (usually 1 tsp per gallon/3.8L). Swirl to mix.
2. Submerge: Lower the blanket into the water. Push it down gently with your open palms until it is fully saturated. You will feel the weight increase significantly.
3. Soak: Let it sit for 10 to 15 minutes. Do not soak longer than 20 minutes; water weakens the fibers.
4. Agitate Gently: Do NOT scrub fabric against fabric. Gently squeeze the soapy water through the fibers. Imagine you are kneading very soft dough. Focus on stained areas by pressing, not rubbing.
5. Rinse (Crucial): Drain the tub. Press the blanket against the tub floor to push out soapy water. Refill with cool water (same temperature as the wash water to prevent thermal shock). Swirl gently. Repeat until no suds appear.
   • Pro Tip: If you have hard water, add ¼ cup (60ml) of distilled white vinegar to the final rinse. This neutralizes alkalinity and dissolves mineral deposits that leave wool feeling scratchy.

Method 2: Machine Washing (Front Loaders Only)

Warning: Only use this method if the care label explicitly states "Machine Washable" or carries the Machine Washable Woolmark. Never use a top-loader with a center agitator; it will destroy the blanket in a single cycle.

1. Bag It: Fold the blanket loosely and place it inside a large mesh laundry bag. This protects the surface from friction against the metal drum.
2. Balance the Load: Wash the blanket alone or with a few light towels to balance the drum. Heavy, wet items can damage machine bearings. (This is similar to the care required when you wash a weighted blanket, where weight distribution is critical).
3. Select Cycle: Choose "Wool," "Hand Wash," or "Delicate."
4. Settings:
   • Temp: Cold / 30°C.
   • Spin: Low (400 - 600 RPM) or No Spin. High spin speeds stretch the wool.
5. Detergent: Pour wool-specific detergent into the dispenser. Do not use pods.

Drying: The Reshaping Phase

The drying process determines the final texture and shape of your blanket. Never hang a wet wool blanket; the weight of the water will stretch it into a distorted diamond shape.

1. The Burrito Method: Lay two large, dry towels on the floor. Lay the wet blanket flat on top. Roll them up together like a sleeping bag. Press firmly on the roll with your knees to transfer water from the wool to the towels. Unwrap and repeat with dry towels if necessary.
2. Block the Blanket: Lay the damp blanket on a mesh drying rack or a clean bed sheet spread on the floor. Gently pull the edges to straighten them. Square up the corners. This is called "blocking"-you are manually setting the dimensions as the keratin hardens.
3. Air Flow: Allow to dry away from direct sunlight and heat sources (radiators/vents). Heat causes shrinkage; sunlight fades dye. Flip the blanket every 6-12 hours to prevent a musty smell.

Maintenance & Prevention

• Airing > Washing: Wool releases odors naturally. Before deciding to wash, hang the blanket outside in the shade for 4 hours. Fresh air often solves the problem.
• Storage: Store cleaned blankets in breathable cotton bags. Never use plastic bins; trapped humidity leads to mildew. Add a cedar block to repel moths.

Wool Care Comparison

Common Mistakes to Avoid

• Using Biological Detergent: Standard detergents (Tide, Persil) contain enzymes. Do not use them. They degrade wool fibers over time.
• Thermal Shock: Moving wool from hot water to cold water causes immediate felting. Keep wash and rinse temperatures consistent.
• Wringing: twisting the fabric breaks fibers. Press water out; never twist.
• Tumble Drying: Even "low heat" can shrink wool. The tumbling action mimics the felting process. Air dry only.

Frequently Asked Questions

Can I use fabric softener on wool? No. Fabric softeners coat the fibers with a waxy residue, reducing wool’s natural breathability and fire resistance. If the blanket feels stiff, use a white vinegar rinse instead to strip mineral buildup.

How do I fix a shrunken wool blanket? It is difficult. Soak the blanket in a bucket of lukewarm water with a generous amount of hair conditioner. Gently stretch the fabric back to size while wet. Pin it in place to dry. This may relax the fibers, but severe felting is permanent.

How often should I wash my wool blanket? Rarely. Once a year is standard. Spot clean spills immediately and air it out seasonally. Over-washing strips the natural lanolin (if present) and wears down the fibers.

Is dry cleaning better than washing? For structured items (like blazers) or lined blankets, yes. Dry cleaning uses solvents that do not swell the fibers like water does. For simple woven throws, hand washing is safe and removes water-soluble soils (like sweat) better than dry cleaning solvents.

Why does my blanket smell like a wet dog? This is the natural smell of wet wool (sheep). It indicates a natural fiber rather than a synthetic one. The smell will dissipate completely once the fibers are 100% dry.