Why Raw Fleece Felted — and Why Yours Doesn't Have To

Felting is permanent. Once those microscopic scales on the wool fibre have locked together, no amount of conditioner, patience or swearing will undo it. But here's the reassuring part: felting needs three things at once — moisture, heat and movement. Add an alkaline detergent and you speed the whole process up. Take away any one of the three and you are safe. Since you obviously need water, your controls are temperature, chemistry and how you handle the fleece.

The rule that governs everything below is simple: keep the temperature consistent, keep the chemistry gentle, and keep your hands still. Most ruined fleeces are not ruined by the wrong detergent. They are ruined by a ten-degree drop between the wash water and the rinse water, or by someone giving the tub a helpful stir.

Skirt the Fleece Before It Ever Gets Wet

Spread the fleece out on a sheet outdoors or on a table, cut side down. Pull away the skirt — the dirty, matted edges from around the belly, back end and legs. Dags, cotted lumps and short second cuts all go on the compost. Shake the fleece well; a surprising amount of straw, hay and grit falls out dry, and every bit you remove now is a bit you don't have to wash.

Don't try to pick out every last piece of vegetable matter at this stage. Much of it loosens in the wash and can be dealt with later when the wool is clean. Now break the fleece into portions of roughly 100–200g. A whole British fleece often weighs between 1.5kg and 3.5kg, and a solid lump of that size won't let water penetrate to the middle. Smaller handfuls, kept in their lock structure, wash far better.

Set Up Your Washing Station

Use the softest water you can get. If you live in a hard water area, rainwater or filtered water makes a genuine difference, because calcium in hard water reacts with detergent and leaves a grey scum that clings to the fibre. Fill your tub deep enough that the fleece will float rather than sit on the bottom, and add the detergent before the wool goes in.

Temperature should be 30–35°C, and never above 40°C. Use a thermometer rather than your hand — hands are unreliable judges, and lanolin starts to melt around 35–40°C anyway, so you don't need more heat than that. Whatever temperature you choose, every wash and every rinse must match it.

• Good choices: a dedicated wool scour, or a mild non-ionic liquid detergent with no enzymes, bleach, brighteners or perfume.
• Poor choices: biological washing powder, ordinary washing-up liquid (often too alkaline), and soap flakes in hard water (they leave scum).
• Never: the washing machine, unless you are very experienced and the machine has a genuine wool cycle. Even then, most fleece in the grease is best washed by hand.

The Wash: Soak, Don't Scrub

Lower the fleece gently into the water and press it under the surface with flat hands. Never pour water onto the fleece, and never let a tap run onto it. Then walk away. Leave it to soak for 20–30 minutes. The water will turn cloudy and yellow as the lanolin and dirt release — that is exactly what you want.

Lift the fleece out in one supported handful, letting it drain over the tub. Tip the dirty water away. Repeat with fresh water and detergent. Two or three washes is typical, and the first is always the filthiest; after that the water gets progressively clearer.

At no point should you wring, rub, stir, knead or agitate the fleece. If you need to move it, move the whole mass gently, or lift it out entirely. The moment you start treating it like laundry, you are felting it.

Rinsing, and the Lanolin Question

Rinse in water at the same temperature until it runs clear — usually two or three changes. A tablespoon of white vinegar per five litres in the final rinse helps shift any detergent residue, provided the water is still the same temperature as everything else.

How clean you take it is a matter of taste. Some spinners want every trace of lanolin gone. Others stop after two washes, leaving a little grease in for softness, elasticity and a degree of water resistance. If the fleece is destined for dyeing or felting, wash until the rinse water is genuinely clear. Whatever you decide, do as little handling as possible while wet.

Drying a Wet Fleece in a British Climate

Drain the fleece in a colander or mesh bag and press it against the sides — never wring. A salad spinner handles small batches beautifully and removes a surprising amount of water. Otherwise, spread the fleece loosely on a drying rack over a sheet or an old net curtain, in a warm, airy room out of direct sun. Turn it gently once a day. Indoors it will take two to four days; an airing cupboard speeds things considerably, but don't lay it directly on a radiator.

Store the finished fleece loosely in a cotton pillowcase or paper sack with a few lavender sprigs, never in plastic, and keep it somewhere dry and mouse-free. A wet February afternoon, with the garden too soggy to bother with, is honestly the perfect time to scour a fleece — and by spring you'll have soft, open wool ready for carding, spinning or dyeing.