Natural Dyeing with Onion Skins and Tea

The Case for Dyeing from the Kitchen

There is something quietly satisfying about pulling a pan of onion skins off the hob and watching a length of cotton turn the colour of honey. Natural dyeing has a reputation for being fussy and expensive, but the most rewarding dyes are often the ones you were about to throw in the bin. Tea bags, onion skins, avocado stones and coffee grounds all contain tannins and pigments that bond beautifully to cloth and yarn, and they cost nothing but a little patience.

This is slow craft in the truest sense. Nothing happens quickly, and that is rather the point. You are not chasing a precise commercial colour; you are working with what the season and your kitchen give you. Below is a practical starting point for anyone with a saucepan they are willing to dedicate to the cause.

What to Save, and How to Store It

Start a collection jar or paper bag in a cool, dark cupboard and add to it as you cook. The golden rule is to dry everything thoroughly before storing it, or you will meet a layer of mould within a fortnight.

• Onion skins — the dry outer layers only. Yellow and brown skins give warm golds and amber; red skins lean towards olive and soft rust. Around 100g of skins will dye roughly 100g of fibre to a solid mid-tone.
• Used tea bags — dried flat on a plate first. Twenty to thirty bags, or three tablespoons of loose leaf, will dye 100g of fibre a pleasing fawn. Cheap black tea works as well as anything fancy.
• Avocado stones and skins — rinse and freeze until you have a bagful. They give the most surprising colour of all: a soft blush pink on wool and silk, and dusty rose on cotton. You need a good quantity, so be patient.
• Coffee grounds — dried on a tray. Reliable, soft browns and greys.
• Optional extras — pomegranate skins, carrot tops, nettles, and the papery skins of garlic.

Avoid beetroot and most berries unless you are dyeing something that will live in a drawer. Their colours are gorgeous wet and disappointingly fleeting once light gets to them.

Preparing the Fibre

Dye will not stick evenly to dirty or greasy cloth. Scour plant fibres such as cotton and linen by simmering them for an hour in water with a spoonful of washing soda, then rinse well. Wool and silk need only a gentle wash in warm water with a pH-neutral soap — never let them sit in hot water that cools suddenly, or they will felt.

Next, mordant. Alum (aluminium potassium sulphate) is the safest and most reliable choice for home dyers. For animal fibres, use roughly 10–15% alum and 6% cream of tartar by weight of dry fibre. For cotton and linen, pre-treat with tannin first — a strong brew of tea or oak gall works well — then mordant at around 15% alum. Dissolve the powders in hot water, add the wet fibre, hold at 80–85°C for an hour, then leave it to cool in the pot overnight. Rinse lightly before dyeing.

Making the Dye Bath

Fill a stainless steel or enamel pan — never aluminium, which will affect your colour — with enough water to let the fibre move freely. Add your dye material and bring to a gentle simmer.

• Onion skins: simmer for 45–60 minutes, then strain out the skins before adding fibre.
• Tea: steep as you would a very strong pot, simmer 30 minutes, strain.
• Avocado: simmer stones and skins for a full two hours, ideally across two days, for the deepest blush.

Add the wetted, mordanted fibre and hold at 80°C for an hour, stirring gently and often. Then — and this matters — turn off the heat and let the fibre sit in the cooling bath overnight. Much of the depth develops in those quiet hours.

Shifting the Colour

Modifiers let one dye bath produce a whole family of shades. Work in a separate pot and always wear gloves.

• Iron water — a few rusty nails left in vinegar and water for a week. It saddens colours towards olive, charcoal and deep bronze. Use sparingly, at roughly 1–2% by weight; too much makes fibre brittle.
• Washing soda — a pinch in the rinse bath turns golds towards rust and apricot.
• Vinegar — brightens yellows and pinks, particularly on wool.

Rinse modified pieces thoroughly in cool water until it runs clear.

Slow Stitching and Finishing

Naturally dyed cloth is rarely flat or uniform, and this is where hand stitching comes into its own. Running stitch, backstitch and simple patchwork celebrate the unevenness rather than fighting it. Use linen or cotton thread, waxed lightly with beeswax to stop it tangling, and let visible mending guide the design — a contrasting patch over a worn elbow, a line of stitches along a hem that shifts from gold to olive.

Wash naturally dyed textiles in cool water with a pH-neutral soap, dry them in the shade, and store them away from direct sunlight. Colours will soften over the years, but a well-mordanted piece will hold its character for a long time. Keep notes of weights, times and temperatures as you go — your future self will thank you, and so will the cupboard full of onion skins you could not bring yourself to bin.