4 Natural Dyes from Kitchen Waste
Natural dyes have been used to colour cloth for thousands of years and until 1856 when William Henry Perkin serendipitously discovered the first chemical dye – Mauve, harnessing the colours from nature was the only way for us to dye clothes.
Natural dyes come in numerous forms and are derived from a wide range of plants and minerals. They have many different properties and can behave quite differently to the synthetic chemical dyes we have all become used to.
As with almost all aspects of textile production, there are pros and cons for every kind of dye whether is it synthetic or natural.
Natural dyes are often criticised for the consumption of large amounts of water, energy, and time in the process – especially when compared to modern-day chemical dyes. Another potential drawback of natural dyes is that some of them require a mordant (a metal additive used to form strong covalent bonds between the dyestuff and the fibre) to improve colourfastness. Some mordants are more safe than others – iron and potassium aluminium sulphate (known as alum) are widely acknowledged to be the least harmful to human health and the environment.
As long as one if careful when handling mordants, natural dyes are an exciting way to create colour from nature and some can even be found in your kitchen waste. This is the most sustainable form or natural dyeing as nothing new was grown or produced, and you still get to eat the food.
It is difficult to produce consistent shades as every natural dye venture is different. This is why natural dyes have taken a backseat industrially speaking compared to synthetic dyes, but this is no reason not to experiment with them on a small scale or at home.
1 – Brown Onion Skin
Once you have chopped your onions and started cooking, chances are the brown papery skins are discarded without much thought. Onion skins are very rich in tannins and because of this they produce a fantastic dye without the need for a large amount of metal mordant. The shades you can expect are brown to orange to yellow and these depend on the amount of onion skins, the length of time spent extracting the dye and whether or not a mordant has been added to the dye bath.
2 – Pomegranate Skin
Pomegranates skins produce a beautiful range of gold, pink and yellow dyes. As with onion skins, they contain naturally high levels of natural tannins and this reduces the need for a mordant. Pomegranates are one of the most fiddly fruits to prepare and so making a dye from the skin would make the effort even more worthwhile. Not only that, but pomegranates need a lot of water to grow and have to be transported miles to be imported by some countries, so finding a use for the wasted skin is an economical use of time, energy and natural resources.
3 – Avocado Skin (and stones)
Avocados have skyrocketed in popularity over recent years and because of this, their cultivation is straining the water supplies of the countries that produce them. It may be difficult for us to personally combat this phenomena, but we can make natural dyes from the skins which respects and further utilises the time, energy and natural resources consumed during a pomegranate’s growth and transportation.
4 – Walnut Shells
Winter is almost upon us and this means that a surge in nut consumption is on the horizon. Some of the previously mentioned natural dyes are derived from very thirsty trees, and walnuts are now different. In fact, in a single year, walnut cultivation in California uses 1 billion cubic metres of water, that figure is around 20% higher than the yearly water consumption of all Los Angeles homes and businesses. Hence making a natural dye from discarded walnut shells would be a good way to respect the water that has been used to grow them. The shades you can expect from this dye are light to dark and rich browns and the dye is so strong that the bath can be used again and again, thus making even more environmental sense.
The technique is simple and is similar for all of these natural dyes:
Extract the colour:
- Find a large metal saucepan, pot or dye bath. Just to be safe – if you decide you are going to add a mordant then you must select an pan that you will no longer use for cooking
- Soak your leftover dyestuff in 3-5 litres of warm water for at least 2 hours. After enough time has past, you should be able to notice the water changing colour
- Place your dye bath on the stove, bring the soaked dyestuff solution to the boil and simmer gently for at least 1 hour to extract the colour from the kitchen waste
- Allow to cool, strain out the dyestuff from the dye bath and there you have it – a natural dye
- If you intend to routinely wear your naturally dyed fibres or desire a brighter, stronger and more wash fast colour, you can add a mordant at this stage. The easiest to acquire and mordant with is potassium aluminium sulphate which can be bought cheaply in chemists or online – it is a white powder that is sometimes called alum or potash alum. Add between 5-10% w.o.f (weight of fabric) and stir well. Be careful when handling and storing the chemical because it is a mild irritant.
Dye your fibres:
- Natural dyes have the best affinity with natural fibres, so prepare to be disappointed if you try these dyes with synthetic fabrics
- As with any method of dyeing, the fibres must be soaked for at least 2 hours prior to entering the dye bath. The longer you leave your fabric/garment to soak, the more the fibres will open up allow the dye in, thus making a more even colour. Some of the most successful natural dye samples I have produced have been when the fibres have been left to soak overnight
- Bring your dye bath to the boil, reduce the heat and simmer
- Carefully introduce your soaked fibres to the bath. There should be enough room for the fibres to move freely inside the pan. A typical 4l saucepan will contain enough space and liquid to successfully dye a t shirt or a metre or two of fabric
- Continue to simmer the dye and the fibres for at least 1 hour. You may have noticed that there are fewer set times or quantities for natural dyeing – but generally the more time spent on each step, the more colourfast and even the colour proceeded will be
- After enough time has passed, turn off the heat, carefully remove your fibres from the dye bath and rinse them under cold water. Remember that natural dyes behave differently to synthetic dyes and the final colour will be reduced by a few shades during rinsing so leave your fibres in the dye bath until they are several shades darker than desired.