I've become an avid spinner over the last few years and have begun to experiment with hand-dyeing.
Sour grass, also known as soursop or soursob is a plant of the Oxalis species and part of the Wood Sorrel family. There are two varieties found in Australia, both are introduced species and classified as weeds. One variety is common in North America, the other originated in South Africa. Either variety can be used successfully for dyeing yarn. I enjoy using weeds and readily available materials such as onion skins for dyeing. They cost nothing, work well, and collecting large quantities is easy and does no harm.
During winter and spring, Oxalis produces abundant yellow flowers. The flowers are excellent for dyeing yarn, producing soft bright yellows. I collect the flowers when they are in bloom and place them in my freezer, sealed in plastic bags. This way I have a ready supply of yellow dyeing material whenever I need it. Not all botanical dye stuffs can be preserved in this way but freezing works well for soursop.
Dyeing yarn using soursop is a two-step process as mordanting is required prior to placing the yarn in the dye bath. I am dyeing both roving and hand spun yarn. The hand spun yarn was spun directly from raw fleece, so it’s important that it is well washed to remove the lanolin. Lanolin can impede absorption of the dye colour, producing patchy results. This dyeing technique works best with protein fibres such as wool and silk.
Mordanting is a process used to prepare fibre to accept dye colours and ensures bright and colourfast results. There are numerous mordants which produce variations in colour result. It is possible to produce a range of colours from one dyestuff simply by using different mordants or adding additional substances before, during or after placing the fibre in the dyebath.
Alum is the most frequently used mordant - it is readily available, inexpensive and non-toxic when used for dyeing.
Alum Mordanting Recipe
For each 4 ounces or 100 grams of yarn.
1¼ teaspoons of alum
1½ teaspoons of cream of tartar
Weigh wool prior to mordanting to ensure you use sufficient alum and cream of tartar.
Soak wool for one or two hours or overnight in plain water.
Dissolve the alum in boiling water and add to a saucepan of cold water.
Dissolve the cream of tartar in boiling water and add to the saucepan.
Place wool in the saucepan and heat to simmering point. Keep at this heat for one hour. Leave wool in the pot overnight, or for a few hours.
Remove wool from pot and rinse carefully in water of the same or similar temperature. Mordanted wool can be stored damp in the fridge or dried and stored for later dyeing.
Preparing the Dye Bath
Once mordanting is complete, it’s time to prepare the dyebath. Partially fill a saucepan with water and add the soursop flowers. You can place the flowers directly in the pan if you choose, but I prefer to put them in a laundry wash bag first. Any botanical dyestuff, if used loose tends to get tangled in the fibre being dyed. As I often dye wool prior to spinning, I find it easier to keep the dyestuff contained in a mesh laundry bag. Stockings can be used as an alternative, but I purchased a set of laundry bags cheaply to use for dyeing.
As an estimate, you will need about the same quantity of dyestuff as fibre for the strongest colour results. So, if you are dyeing 100 grams (4 ounces) of yarn, you will need 100 grams of soursop flowers. Don’t despair if you have less flowers than this or want to dye a larger quantity. You will still get a result, but the colour produced will be lighter.
Place your flowers in a pan of water and bring the water to boiling point. Keep on a low boil for about an hour. Your dye pot (or vat) should show yellow to orange coloured water if you scoop some up with a stainless-steel spoon. Cool the dye bath to room temperature before adding your yarn.
Dyeing Your Yarn
Once the dye bath is at room temperature, it’s time to add your yarn. You can remove the dye stuff if you prefer, by draining the water through a sieve however if left in the pot it will produce a stronger colour.
Heat the pan so the water is just below the boil. Keep it on a low heat to maintain the temperature for an hour. You can move your yarn around gently from time to time but try not to agitate it (this can lead to felting).
Remove the yarn or fibre from the pan with a pair of tongs or a long handled spoon. Leave to cool until it reaches room temperature - this is important - sudden changes of temperature will shock the fibre and could result in felting.
Once your yarn or fibre at room temperature, rinse thoroughly in cool tap water, then allow it to dry naturally. Enjoy your new sunshiny colour! Dyeing with botanical dyes is fun and can produce excellent results.
© 2021 Nan Hewitt
Liz Westwood from UK on March 28, 2021:
This is an interesting and well-documented article. You give a fascinating and detailed description of the dyeing process.