How to Make Natural Dyes from Kitchen Scraps

There’s something quietly magical about pulling colour out of a pot of onion skins. No bottles. No labels. No synthetic anything — just kitchen scraps, a bit of heat, and fabric that comes out looking like it grew that way. Natural dyeing rewards patience and punishes nothing. Even a messy first attempt usually gives you something wearable, or at least something you’ll want to photograph.

This project is worth making because it’s cheap, forgiving, and endlessly repeatable. You probably already own most of what you need. The colours shift with the seasons, the water, and even the pot you use. You’ll end up with one-of-a-kind cloth and a new way of looking at your vegetable peelings. Ready to raid the kitchen bin?

Materials List

• Plant material for dye: onion skins (yellow or red), avocado stones and skins, beetroot, red cabbage, turmeric powder, black tea, coffee grounds, or marigold petals. Fresh or dried both work.
• Natural fibre fabric or yarn: cotton, linen, silk, or wool. Synthetics won’t take the dye well, so save those for another project.
• A large stainless steel or enamel pot: don’t use aluminium or cast iron unless you want the metal itself to change your colour. A dedicated dye pot is ideal so you’re not cooking soup in it later.
• Mordant: alum powder (aluminium potassium sulfate) is the easiest and safest for beginners. Cream of tartar is a useful partner. For a no-mordant alternative, use strongly coloured materials like turmeric or black tea.
• Non-iodised salt: helps dye take to cotton and linen.
• White vinegar: the go-to for wool and silk.
• Wooden spoon or tongs: reserved for dyeing only.
• Rubber gloves: turmeric will stain your hands for days. Trust me.
• A colander or sieve: for straining out plant bits.
• Old towels or newspaper: for drying and protecting surfaces.
• A notebook and pen: you will forget your ratios. Write them down.

Step-by-Step

1. Weigh your fibre dry. This matters more than anything else. You’ll use roughly 10–20% of the fibre’s weight in alum, so a 100g skein of wool needs about 10–20g of alum. Write that number down before you do anything else.
2. Scour the fabric. Wash your fibre thoroughly with a gentle soap to remove oils, sizing, and factory gunk. Rinse well. Dye can’t grab onto dirt.
3. Mordant your fibre. Dissolve your alum in a pot of warm water — about 4 litres per 100g of fibre — and add a pinch of cream of tartar. Bring it to a gentle simmer, add the wet fibre, and hold it there for about an hour. Stir occasionally, but don’t agitate wool or it’ll felt.
4. Let it cool overnight. Yes, overnight. Rushing this step gives patchy results. The fibre should sit in the mordant bath as it cools down slowly.
5. Prepare your dye bath. While the fibre rests, simmer your plant material in water for 30–60 minutes. Onion skins need about 20 minutes. Avocado stones want a good hour. Red cabbage is fast. Strain out the solids unless you want speckled fabric — some people love the speckles, so this is your call.
6. Add the fibre to the dye bath. The dye liquid should be warm, not boiling. Submerge your fibre fully and keep it moving gently for the first few minutes so the colour goes on evenly.
7. Simmer low and slow. Hold the bath at a gentle steam — around 80°C — for 30 to 60 minutes. Longer equals deeper colour. Check every 15 minutes by lifting a corner with your tongs.
8. Turn off the heat and let it sit. Leave the fibre in the cooling bath for anywhere from two hours to overnight. This is where the real depth develops.
9. Rinse in cool water. Rinse until the water runs clear. Don’t use hot water here — it can shock the fibre and strip colour.
10. Wash gently and dry in shade. Use a pH-neutral soap, then hang to dry away from direct sun. Sunlight fades natural dyes faster than anything.

Beginner Tips

Skip the mordant and your colour will wash out within a few weeks. I know it feels like an extra step. Do it anyway.

Don’t use your favourite cooking pot. Even a well-scrubbed dye pot can leave a faint tint behind, and some mordants aren’t food-safe once they’ve been heated. Charity shops are full of cheap stainless steel pans.

Stop stirring wool like it owes you money. Wool fibres lock together when they’re hot and agitated. Fold it in gently, or better still, don’t touch it at all once it’s in the bath.

Weigh your materials. A “handful of onion skins” is not a measurement. Two hundred grams of skins in four litres of water will give you a completely different colour from fifty grams. Consistency is what turns a lucky accident into a repeatable recipe.

Don’t judge the colour while the fibre is wet. Wet fabric always looks darker and more saturated than dry fabric. Wait until it’s fully dry before you decide whether to overdye.

Creative Variation

Here’s my favourite twist: bundle dyeing. Instead of simmering everything together, lay your mordanted fabric flat, scatter petals, onion skins, and rusty nails across one half, fold it over, roll it up tightly, and tie it with string. Steam the whole bundle for an hour, then unwrap it. You’ll get unpredictable, marbled patterns that look nothing like a flat dye bath — more like a map of somewhere you’ve never been. It’s the one technique where a “failed” result often looks better than the planned one.

Troubleshooting

The colour is too pale. Either your dye bath was weak or you didn’t simmer long enough. You can overdye the fibre in a fresh, more concentrated bath. More plant material, less water, longer time. It’s rarely too late.

The colour is blotchy. Usually caused by fibre that wasn’t fully wet before it went in, or by packing it too tightly in the pot. Soak your fibre in plain water for an hour first, and give it room to move.

The colour rubs off on your hands. That’s called crocking, and it means the dye hasn’t bonded properly. A longer mordant bath or a post-dye soak in a weak vinegar solution (for protein fibres) usually fixes it.

The colour vanished after washing. Mordant problem, almost certainly. Double-check your ratios and make sure you simmered the mordant bath rather than just dipping the fibre in warm water.

Your pot turned a weird colour. Aluminium and iron pots react with plant dyes. That’s fine if you want the reaction — iron darkens colours beautifully — but confusing if you don’t. Stick to stainless steel or enamel.

Nothing happened at all. You’re probably working with a synthetic fabric. Check the label. If it says polyester, it’s not going to work, no matter how long you simmer it.

Natural dyeing is slow, a bit smelly, and wonderfully unpredictable. That’s the whole point. Start with onion skins this weekend — they’re free, they’re everywhere, and they’ll give you a soft golden yellow that makes you wonder why anyone ever bought a bottle of dye. Once you’ve seen your own kitchen waste turn into colour, you’ll never look at a beetroot the same way again. Go on, put the kettle on and raid the veg drawer.