Food Waste Dye - Onion Skins

Food Waste Dye Workshop Flyer. Onion Skins. 3/31 11am pst Instagram Live @eastweststuff and TikTok Live @eastwestshop

Dyeing with Onion Skins

Natural dyeing and tie dyeing are a fun way to cover stains on stained clothing and/or cloth napkins and rags

The goal of this post is to not overwhelm you with information or teach you a long list of things that you HAVE to do for natural dye.  The truth is that if you leave a dye material in a bucket with some water in the sun the dye will naturally extract.  And if you leave cloth in that bucket it will dye as well.  The color, depth of the color and how long the color lasts will vary based on your technique.  But the LONG list of technique options should not keep you from dyeing!  It's fun and easy and also good for you and your skin!

Many food waste items we can dye with -  including onion skins, pomegranate skins and Avocados -  have even more nutrients and beneficial compounds in them than the parts we eat.  Research has shown that these beneficial compounds can actually be absorbed by your skin.  Essentially acting as anti-oxidents for your skin.  As these compounds break down in your garment your skin may be able to absorb them - fighting free radicals.  Learning this has changed my relationship with natural dye.  It feels important to try and use it whenever possible as opposed to a chemically derived conventional dyes.  Conventional dyes - that we use for almost all of our dyed clothing - have a skull and cross bones warning label on the box.  So the idea that dyes could actually prevent waste, and at the same time potentially HELP you makes it all the more important!  

Onion skins get their color from the flavonoid Quercetin.  Quercetin is taken orally as an herbal supplement as well as included in topical skin products to fight free radicals and help reverse aging.  So why not try and infuse our clothes with it rather than throwing it into the trash!

What to Dye

Any garment, fabric or yarn made of natural fibers can be dyed.

  • Cellulose (made from a plant) Cotton, Linen, Rayon, Hemp, Bamboo, Tencel
  • Protein (made from animal) Silk, Wool, Cashmere, Mohair, Feathers

(Synthetic fibers like polyester are made of plastic and will not accept natural dyes) 

Natural dyes are not as "potent" as conventional dyes.  The best fibers to dye are light colored.  It is possible to dye darker materials or materials that have been previously been conventionally dyed.  The results will vary depending on the color and depth of the natural dye.

Used Clothing has been exposed to an unknown amount of things that make affect the dye. Sometimes unknown stains will “appear” when you natural dye. For instance - Oil stains on a tee introduce protein onto a cellulose fiber so the stained area will appear darker and brighter.  Aluminum is a mordant/modifier for natural dye. Many deodorants have aluminum in them - so the armpits of a tee may also appear darker and brighter than the rest of the shirt. Tie dyes and dyeing to a darker color can sometimes be used to cover this up.  It always presents an opportunity to be creative!

Materials Needed

  • Fibers to Dye (see notes above)
  • Onion Skins - Papery outer colored part of Yellow and/or Red onions.  They produce different colors so store and dye with them separately.  I keep a jar in the cupboard and collect onion skins anytime I peel an onion.  Remember we're only dyeing with the papery colored part of the onion.  If you keep only this part you should avoid too much mold.  Mold will decompose the skins and weaken the dye but you can still use them.  If this happens just rinse prior to use.
  • Vessel to Dye in - Should not be used for food consumption after dye. For Heated dye stainless steel is best. Aluminum and Copper can be used but may alter the color
  • For Solar Dye - a bucket or repurposed jars
  • Heat Source
  • Tongs, Ladle, Strainer (I find these at thrift shops!)
  • Gloves
  • Mordants/ Scouring agents* (Face Mask required for chemical mordants)
  • Rubber Bands, Strings and other tie dye supplies*


Optional additonal steps (to increase colorfastness and color absorption)

  • Scouring - Cleans the fibers of oils and waxes.  Can be important for the fiber to "take in" the dye.  If the fibers aren't scoured the dye may adhere to the oils and waxes and will either not adhere properly or will wash out with those fibers.  This part of the process is also time consuming and uses more water and materials - so I choose which styles to scour as I go.  For majority of rag shirts and used napkins I do not scour and choose to work with what comes.  Botanical Colors has a complete list of 
  • Mordants - Assists in the connection between the dye + the fiber.  This will help the color adhere with more vibrancy and will help it last longer.  Mordants for cellulose and protein fibers are different.  Some mordants are aluminum based and require the use of a mask or respirator while working. Soy milk can be used as more natural mordant but also requires many extra steps.  For this reason I mordant when it feels necessary and I also experiment with results without mordants.  Especially when dyeing rag tees and cloth napkins.  I think it's great to see what's possible with the lowest environmental and health impacts.
  • Tannins - Combined with mordants will produce the richest and darkest color.  Tannins can be found in many natural things.  Oak Galls - small balls that grown on oak trees formed by a type of wasp are one of the strongest natural mordants.  I love finding and collecting these at my local park!  Avocado pits also contain tannins.  Some people say mordants aren't necessary when dyeing with avocado because the tannins will help the color adhere to the fiber.
  • Modifiers- Elements like Iron or Copper can be added to shift colors.  Iron is one of my favorite modifiers to work with.  I use both powdered iron and also an iron extraction that can be made from rusty items, vinegar and water.  Iron will "sadden" the color and make it shift from its dyed color to a more grey version.  Sometimes the effect will produce army green, greys or even black.  Items dyed with iron require 3 garment washes before wear to remove all the iron from the garment. 


It is possible to dye without mordants - however if you are aiming for the longest lasting color mordants will help. Mordants will also help to brighten or shift the color.

The mordant I use for Cellulose fibers is Aluminum Acetate with Calcium Carbonate afterbath. Directions and a chart on additional mordants is available from Botanical Colors.

When dyeing Cotton I tend to use approximately 6-8 rounded Tablespoons of Aluminum Acetate for a 5 gallon bucket of warm water.  The goal is 5-10% of the Weight of the Fiber (WOF) for the best results.  When I first started my natural dye journey I used to weigh the fibers.  And if I have something REALLY important I'm dyeing I may do that again - however I love the creativity of being fluid.  So this mordant number is flexible.  I also reuse the mordant bath until it starts to get yellow or brown.  Let it soak in the mordant for minimum 30 minutes but up to 24 hours.  The longer it sits - the more time the fabric has to take it in.  

Once the fiber is completed in the Aluminum Acetate bath wring out all excess fluid back into the mordant bucket.  And then dip it into a Calcium Carbonate bath.  This bath is prepared with 1-2 rounded TBSP of powder for a smaller bucket/bowl of hot water.  Leave it in this bath for minimum of 15 mins.  Wring back into the bath and then rinse quickly.  Set aside for dye or tie it up for tie dye.

Preparing the Garments for Dye

Preparing the material for dye Fibers should be pre-washed and wetted again before dyeing If you have chosen to Mordant your goods this should also be done ahead of time. (Modifiers can be done post dye) Use string, rubber bands, etc to tie up the garment for a desired tie effect.  There are many different ways you can tie the garment.

Keep in mind that anywhere the garment folds or is tied or banded it will resist the dye.  Use this in your favor to make patterns or resists that will help hide stains if you have them!  See below for examples of stains and the ways we tried to hide them.

Making the Dye- Heated Version

  1. Fill pot/bucket with water - we like to capture rain water to use for this but filtered or tap water will work. The PH of the water may affect final colors.
  2. Add onion skins to the pot - breaking up the onion skins into smaller pieces.  Use as many as possible for the darkest color.  I used about 2-3 cups of skins for a 5 gallon vat.  
  3. Heat on Medium/High heat to gently coax out the color - to a slow simmer for 30-60 minutes
  4. Use your spoon to check to see if the water is becoming colored with the dye. Onion skin dye extracts fairly quickly
  5. At this point once you can choose if you would like to strain out the dye materials. Strained dye will produce a solid color. Leaving the dye stuff in the pot will produce little spots of darker color and an uneven color. I love to see all the little bits of color like confetti so most of the time I leave the dye stuff in the pot.  (Tip: If you don't have a lot of time you can also add the fibers in at the same time as the skins and let them develop together)
  6. Add prepared goods to the pot. Color may start to develop quickly but sometimes takes more time... leave the goods in for a minimum of 15 minutes.
  7. The longer you can leave them the better. Typically when I’m done dyeing for the day I turn off the heat and leave the goods sitting in the dye overnight. 
  8. Wring out and then rinse the goods with water.  Wash with gentle detergent in cold water.
  9. After dyeing strain out the leftover bits of skin and add them to your compost bin.


Making the Dye- Bucket Version

  1. Add onion skins to a bucket or repurposed jar or other heat tolerable container. As you add them - break them up into small pieces
  2. Heat water to boil/simmer and then pour over the dye stuff and let it sit Be careful handling the container until the water has cooled.  At this point once you can choose if you would like to strain out the dye materials. I typically leave the onion skins in the container.  I don't mind the small bits and marks that the skins leave behind.
  3. Add prepared goods to the container. Cover and let it sit. I like to put my 5 gallon buckets in the sun to help keep them warm. Avoid clear containers in direct sun as the UV rays will deteriorate the dye
  4. Be patient with non-heated dyes and give them to develop and soak into the fabric with time and the sun's heat.

Caring for your Naturally Dyed Garment

Natural dyes are... natural.  Like a leaf left to sit in the sun - these garments will also deteriorate under the Sun's rays.  

Stain Coverup Examples

  • Cashmere Sweater with brown circular stain on left chest.  Was unable to remove stain with washing...  Dyed by crumpling the garment and then tying it with rubber bands.  



    • More to come!  Stay tuned...

    Other Food Waste Dyes

    • Avocado Skins and Pits
    • Pomegranate Skins

    Some reference resources to find out more...

     Thank you to LA City Sanitation Department and the CA Product Stewardship Council for sponsoring this post.  Let's all work together to reduce waste in our communities!