An Intro to Food Waste Dyes
by Wesley Scott
How many of us really know how our clothes are made? Or more specifically, how they are dyed? I’m sure we've all heard the horror stories of colored rivers that run near textile mills or the health concerns for workers working in these mills, but what other options are there? Let’s also consider food. How many times have you finished a meal only to see how much waste was created in the process? How many times have you opened the refrigerator just to realize all that produce you bought last week has gone bad? I’m sure the amount is innumerable. Consumers are searching for a new purpose behind what they consume, whether that be clothing or food. With the simultaneous, but independent, growth of both the slow fashion movement and the slow food movement, there’s a bridge that can be made between the two: dyeing textiles and clothing with food waste. While there are no ideal industrial scale solutions at this point, using food waste dyes is an easy process to do yourself, allowing you to reduce waste and breath new life into old clothes
For any of us concerned with sustainability, waste is a constant, nagging concern. And rightfully so. But how often do most of us think about food waste? Well, it should be at every meal. The USDA reported that 30-40% of all produce in the US is thrown away. Even worse, a 2014 report from the USDA estimated the value of that waste in 2010 at $161 billion. While much of this is from being uneaten, there is still the issue of how to best utilize food scraps and waste in the cooking and preparing process. As sustainability has entered the mainstream, composting has become the defacto way to deal with food waste. An EPA report from 2017 found that composting tonnage had increased by 15% since 2015. While the numbers show that people are taking the initiative to deal with their wastes, there still needs to be other, more engaging ways to handle food waste.
The fashion industry is often cited as one of the worst environmental polluters and the industry has rightfully earned that title. Fashion’s pollution problem is present at every step of the supply chain but it’s the dyeing process that’s the most visible - literally. Look at the water color near many dye facilities or mills in countries with lower regulations (which also tend to be where most clothing is produced) and you’ll be able to see the pollution right away. Many of these facilities use AZO dyes, synthetic dyes that make up 70% of commercial dyes, and these dyes are known to be harmful, both to the planet and to our health. The EU, along with many other nations, have banned these dyes after it was discovered that the dye could break down into 24 possible carcinogens. The entire textile industry is estimated to expel 200,000 tons of dyestuff annually, according to a report from the House of Parliament. This same report found that AZO dyes, when expelled in wastewater, contribute to and can cause “growth reduction, neurosensory damage, metabolic stress and death in fish, and growth and productivity in plants”. The industry is obviously in need of a new dye solution. While there are many interesting dye innovations, maybe it’s best to consider the way things used to be done.
Food waste dye is nothing new—it’s been utilized for hundreds of years. For example, black walnut hulls were used as far back as the Viking age. A new movement has evolved in natural dye circles to utilize food waste dyes as an important part of their practice. Natural dyers like Cara Marie Piazza and Maria Elena Pombo, both Brooklyn based, have developed long standing practices with food waste dyes. Restaurants have even taken notice of this movement. Lighthouse restaurant in Brooklyn collects certain food waste items like avocado skins and pits, carrot tops, beets, and onion skins so that natural dyers can use them. There are also waves in the industry with less artisanal, more scalable approaches. One example is Kaiku, a project from Nicole Stjernswärd focused on processes to turn fruit and vegetable scraps into a powder pigment that can be used on an industrial level.
Food waste dyes are better for the planet, better for your skin, and bring us that much closer to the clothes we wear. With just a little practice, you too can create beautiful colors from the comfort of your home. Avocado skins and pits, onion skins, pomegranate rinds, many herbs, carrot tops, beets, walnut hulls, and a wide variety of other foods can be utilized for dye. For a beginner, avocados serve as the perfect introduction to food waste dyes. They provide a wonderful faded pink color and don’t require some steps that will be necessary with other dyes, like mordanting. Most natural dyes will need some sort of mordant, a fixative, to prepare the fabric for dyeing but avocados do not, making them an easy first foray into the world of natural dyes. It’s simple and many of us eat enough avocados to easily collect what you need.
Materials:
Avocado skins or pits (or both)
Stainless steel pot (dye exclusive pot)
Salt (optional)
Heat source
Pre-washed fabric or item of clothing
Step One: Prep your clothing/Fabric. Pre-wash your fabric or clothing with your favorite detergent. Any oils or stains will show up boldly with natural dyes so clean fabric is a necessity. The tannin in the skin and pits acts as a mordant but for other food waste dyes a mordant might be necessary.
Step Two: Prep the avocados. Carefully clean all residue off the pits and skins. Any bit of avocado flesh can be challenging to remove from the pot, and can hinder the ability for the cloth to take the dye evenly.
Step Three: Prepare your dye. Add your cleaned skins and pits to a stainless steel pot with enough water to let them float freely. Make sure this pot is used exclusively for dyeing- textiles can have finishing chemicals on them that you don’t want to ingest if the pot is later used for food. Dye extraction times vary, but I generally prefer to simmer the dye bath for about an hour before taking it off the heat, covering, and letting it sit overnight. Remember, the more avocados, the stronger the dye. At its lightest, it may look like a simple faded pink but it can reach deep coral hue with more dyestuff.
Step Four: Strain the skins and pits. Fish out the skins and pits from the pot and make sure there are no pieces left.
Step Five: Submerge your fabric in the dye. I follow the same process here as making the dye. Simmer the fabric in the dye bath for about an hour before taking it off the heat and covering and letting it sit overnight. The longer the fabric is in the dye, the deeper the color you will be able to achieve. If you want a lighter color, a couple of hours will suffice.
Step Six: Remove the fabric. Once the item has reached an optimal shade, remove it from the pot. Since the color will be darker when wet, imagine the item one or two shades lighter when dry. Then, remove it from the pot and ring out all the excess water and dye.
Optional tip: To prolong the longevity of the color, prepare and use a salt bath fixative. Salt water acts as a fixative for cellulose (cotton, linen, etc.) fibers. Any protein fibers like wool will not need a fixative. A simple salt and water mixture will work in a tub or bowl that can fit your item. A quick submersion and movement around will be enough to set the dye.
Step Seven: Hang to dry. After the dye process is all done, hang or lay your item to dry. Natural dyes are not completely lightfast so allow the items to dry in a shady spot and out of direct sunlight.
We know we need sweeping changes in both the fashion and food industries, but while we wait, we can lead the charge in our own lives. Food waste dyes offer an opportunity to reinvigorate our closet and deal with our waste. It’s an opportunity to engage with these problems in an enjoyable way. Next time you think of getting rid of that stained white shirt, save those avocado pits and skins and rejuvenate that shirt before composting.