Dyeing Wool with Natural Kitchen Ingredients

Why Kitchen Dyeing Suits Wool and Yarn

There is something quietly satisfying about lifting a skein of undyed wool from a pan of simmering onion skins and watching it turn the colour of an old copper kettle. Natural dyeing is not a laboratory pursuit; it is a store cupboard craft, and it has been for centuries. Onion skins saved through the winter, the dregs of the teapot, a few tired beetroot and a handful of coffee grounds will all give you colour on protein fibres such as wool, alpaca, silk and mohair.

What you need is patience rather than precision. A stainless steel or enamelled pan, a wooden spoon reserved for dyeing, a thermometer, and a willingness to write things down. Wool is generous, but it is also sensitive: it will felt if you bully it, and it will sulk if you rush the heat. Treat it gently and the kitchen will reward you with soft golds, warm browns, dusty pinks and gentle greens that sit happily together in stripes and colourwork.

Mordanting: The Step That Makes Colour Stay

Most kitchen dyes are what dyers politely call fugitive. Without help, the pigment clings loosely to the surface of the fibre and washes away within a few wears. A mordant acts as a bridge, binding pigment to protein, and it is the difference between a fleeting stain and a colour you can trust.

The workhorse is alum (aluminium potassium sulphate), used at roughly 10 to 15 per cent of the dry weight of your fibre, with 5 to 8 per cent cream of tartar alongside it. For a 100g skein, that means about 12g alum and 6g cream of tartar. Dissolve both in hot water in a pan large enough for the fibre to move freely, top up with warm water, then soak your yarn for half an hour first so it wets through evenly.

• Enter the fibre at around 40 to 50°C, then raise the heat slowly to 80 to 85°C.
• Hold it there for 45 to 60 minutes, lid on, without stirring roughly.
• Turn off the heat and let everything cool in the pan overnight.
• Squeeze gently, never wring, and rinse in water of the same temperature.

Keep dedicated dye pans. Once a pan has held alum or iron, it should not go back to cooking Sunday lunch.

Onion Skins: The Dependable Copper Gold

If you dye only one thing this year, make it onion skins. They are free, endlessly available and remarkably reliable. Roughly 30g of dry brown or yellow skins, the papery bits from eight to ten onions, will dye 100g of wool. Simmer them in water for 45 to 60 minutes, strain, then add your mordanted fibre and simmer gently for another hour.

On alum-mordanted wool, brown onion skins give a clear gold through to deep copper, depending on how long you leave the fibre in the liquor. Red onion skins behave quite differently, shifting towards olive, bronze and khaki, and occasionally a soft verdigris on wool. If you want a deep olive-brown, a small splash of iron water will do it. Make iron water by steeping a few rusty nails in vinegar and water for a week, but use it sparingly: too much iron makes wool brittle and harsh to the touch.

Tea, Coffee and Beetroot: Warm Browns and Fleeting Pinks

Black tea is the other great kitchen standby. Ten to fifteen teabags, or 30g of loose leaf, brewed strongly and simmered with mordanted fibre for about 45 minutes, gives tan, beige and warm mid-browns. Overdye a golden onion-skin skein and you get a rich honey-brown. Green tea leans pale yellow-green, while rooibos gives a soft orange-brown. Coffee grounds behave much like tea, though the colour is slightly duller and benefits from a longer soak.

Beetroot is the romantic of the group. Grated beetroot or peelings will give a dusty rose on wool and something brighter on silk, but keep the heat low. Boiling destroys the pigment, and a splash of white vinegar helps hold the pink. Be realistic, though: beetroot pink fades in sunlight within weeks. Enjoy it as a seasonal colour for a hat or a pair of mittens, not for an heirloom blanket.

Heat, pH and Rinsing Without Felting

The golden rule with wool is never to boil it and never to shock it. Keep the dye bath at a gentle simmer, no higher than 85°C, and avoid sudden changes in temperature. Agitation plus heat plus alkalinity is the recipe for felt, so stir only occasionally and with a light hand.

pH is your quiet adjusting tool. Acids such as white vinegar brighten yellows and pinks, while a pinch of soda crystals or chalk deepens tones and can nudge them towards green. Split a skein in two and test both if you are curious. Rinse in water at the same temperature as the dye bath, gradually cooling, until the water runs clear, then dry in the shade: sunlight fades many kitchen dyes surprisingly quickly.

Keeping Notes and Testing Small

Before committing a whole jumper's worth of yarn, dye a 10g sample. Record the fibre, the mordant, the dye quantity, the water, the pH, the times and the temperatures. Hard water, which much of the UK has in abundance, shifts colours noticeably, so rainwater collected from a butt is worth using for beetroot and other delicate pinks.

Expect your colours to soften with washing. Hand wash cool with a pH-neutral soap, dry flat, and treat the results as living colour rather than a fixed finish. A notebook full of samples is the most useful thing you will ever build, and it is far more satisfying than a shelf of bought dye. Start with onion skins and a rainy afternoon, and see where the pan takes you.