There’s a reason this keeps happening, and it isn’t your machine’s brand or a mysterious curse. The root cause is a single, avoidable move that loads fragile yarns with extra stress, especially in wool, cashmere and acrylic blends.
Why your jumper is sagging after the spin
When knitwear leaves the machine, water still trapped in the fabric adds weight. Hang that weight from the shoulders or cuffs and gravity does the rest. Loops stretch. Necks gape. Sleeves lengthen. Once fibres creep, much of that distortion stays put.
A mid-weight jumper might weigh 500 g dry. After a gentle spin, it can still hold 50–80% of its dry weight in water. That’s an extra 250–400 g pulling down from a hanger or washing line. The looser the knit, the bigger the drop. Cashmere and airy merino are especially vulnerable.
Never hang a wet jumper. Dry it flat, fully supported, so the fabric bears its weight evenly not from the shoulders.
Many households reach for a hanger because it’s quick and tidy. In knitwear care, speed kills shape. The single biggest shift you can make is to stop suspending wet knits altogether.
Smart washing that protects the fibres
Shape starts in the wash. Gentle mechanics and cool water reduce stress on the yarns and limit the water you need to remove later.
- Choose a wool or delicate programme with cool or lukewarm water (20–30°C).
- Use a wool-safe liquid detergent. Skip fabric softener; it relaxes fibres too far.
- Wash similar weights together to stop heavy items dragging on lighter knits.
- Turn jumpers inside out to shield the surface and reduce pilling.
- Keep the load small so the garment can move without stretching.
Temperatures and spin: what the numbers mean
Cool water keeps fibres stable. High heat can shrink wool and destabilise blends. Spin speed matters too. You want enough to remove water, not so much that you twist the garment out of true.
800–1000 rpm is the sweet spot for most knits. Above 1200 rpm, yarns twist and seams torque, inviting distortion.
| Fabric | Wash temperature | Spin speed | Detergent | Drying |
|---|---|---|---|---|
| Merino wool | 20–30°C | 800–1000 rpm | Wool-specific liquid | Flat on towel or mesh rack |
| Cashmere | Cold to 20°C | 600–800 rpm | Gentle wool wash | Flat, reshaped carefully |
| Cotton knit | 30°C | 800–1000 rpm | Mild liquid | Flat, avoid radiator |
| Acrylic/poly knit | 30°C | 800–1000 rpm | Delicate wash | Flat, out of direct heat |
| Wool blends | 20–30°C | 800–1000 rpm | Wool-safe liquid | Flat, adjust to shape |
The flat-drying method that keeps shape
Drying flat supports every stitch. You control the outline while moisture leaves the fabric at a steady pace.
- As soon as the cycle ends, lift the jumper from underneath. Don’t grab it by the shoulders.
- Lay it on a clean towel. Roll the towel up and press to remove extra water. Do not wring.
- Transfer to a dry towel or a mesh drying rack. Smooth the body and sleeves to their original size.
- Align seams, straighten ribbing and nudge the hem back into place with light hands.
- Turn the jumper once mid-way through drying for even evaporation.
Shape it once, then leave it alone. Constant fiddling stretches stitches and creates new distortions.
Speed up drying safely
Place the rack near moving air, not heat. A circulating fan or an open window shortens drying time without frying fibres. A dehumidifier in a small room can halve drying time on damp days. Avoid radiators and tumble dryers; direct heat can shrink wool and bake in twists.
Everyday habits that save money and clothes
Most knits don’t need washing after every wear. Air them between uses and brush the surface to lift fibres. Pilling combs remove bobbles without harming the fabric. Fold jumpers for storage; hanging creates shoulder bumps and slow stretch.
- Air after wear for a few hours on a flat surface.
- Fold and stack; never hang knitwear, even when dry.
- Use cedar or sealed bags in storage to deter moths.
- Keep loads light and similar in weight to prevent drag.
- Spot-clean cuffs and collars to reduce full washes.
Where does the £120 come from? Replace one mid-range jumper at £60 because it went saggy, then repeat the mistake with another before spring. That’s £120 gone, plus the time and hassle. Multiply that across a household and a few winters and the numbers bite harder than the frost.
Emergency rescue when a knit has stretched
You can often improve a stretched jumper. Soak it in cool water with a wool detergent for ten minutes. Support it as you lift. Press out water in a towel roll. Lay it flat and match it to a jumper that still fits, using that garment as a template. Pin edges lightly if needed and leave it to dry fully. For an overgrown neckline, a discreet row of elastic thread inside the rib can restore grip. If the cuffs have blown out, a tailor can tighten ribs without changing the look.
Extra care for longer life
Measure a favourite jumper that fits you well: chest, length and sleeve. Keep those numbers handy. After each wash, shape to that template. This simple habit locks in consistency. For delicate cashmere, rotate wears and give each piece a day to recover. For heavy Aran knits, dry on a mesh rack so air circulates underneath and drying time shortens without heat.
Fold, don’t hang. Air, don’t over-wash. Dry flat, don’t rush heat. These three rules protect every stitch.
If humidity is high, cluster a dehumidifier, a fan and a mesh rack in a small room to create a quick-dry zone. Energy use stays modest, fabric stays calm and your knits keep their clean lines into March. Add a simple fabric shaver, a wool-safe detergent and a sweater comb to your laundry kit. With these tools and the flat-dry routine, you extend each jumper’s lifespan by seasons, not weeks.
