Whether you are dyeing hand-spun or commercially spun shop-bought merino wool, you'll want to be as educated on the process as possible to help the project go smoothly and get the best results. Because all wool is a protein fibre, use an acid dye and a vinegar solution as your dye fixative. Prepare your supplies ahead of time to complete the dye process and, since because merino wool is so soft, work gently with your yarn in every step to avoid felting the wool.
Place the yarn in a large bowl filled with warm water and approximately 2 ml (1/2 tsp) of washing-up liquid. Mix the detergent and water with the wool, but don't make the water sudsy. Make sure the yarn is completely saturated and under water, adding more water if needed to cover the wool. Allow the yarn to soak for 20 minutes.
Determine how dark you want your dye to be. In a plastic container add 2 ml (1/2 tsp) of dye for a light shade, 5 ml (1 tsp) to create a standard shade, or 7 ml (1 1/2 tsp) of dye to make a dark shade. Use a metal spoon to mix the dye into a paste before adding it to the water.
Add approximately 125 ml (1/2 cup) of boiling water or more to your paste and stir continually until all of the dye powder has dissolved. Put 3.8 litres (4 quarts) of water into your large pan and heat it on the hob.
Add the mixed dye liquid to the heated water when it is warm. Add to the dye and water 236 ml (8 fl oz) of white vinegar and stir well. Lift the yarn from its water bath and allow excess water to drain off until it stops dripping without letting the yarn dry. Slowly lower the yarn into the dye with a wooden spoon.
Heat the pan of dye and yarn until the dye begins to simmer. Do not heat it so much that the liquid boils. Set a timer for 25 to 30 minutes once the liquid starts to simmer. Stir the yarn slowly for the first 10 minutes to ensure all of the fibres come into contact with the dye.
Allow the yarn to soak up the dye until the timer goes off. Ideally, the yarn will have soaked up all of the dye, leaving behind clear liquid. Magenta and turquoise may leave some residue behind.
Lift the yarn out of the liquid with a wooden spoon. Rinse the yarn in hot water, lowering the temperature slowly until the water is running clear and you are rinsing with cold water. Squeeze out the excess water and hang the yarn to dry.
Always wear gloves and old clothing when working with dyes to protect your skin and avoid ruining your clothes.
Experiment with different colours, dye concentrations and times to get an idea of the different shades of merino wool you can produce and find your favourite results.
Wipe up any spills immediately with a paper towel to avoid staining your kitchen or work space.