Hannah Thiessen

Posted on: How to dye yarn SparkJune 24, 2021

Natural Dyes for Wool: Madder

Madder is perhaps one of the few very well-known natural dyes, outside of indigo. This is in part because of its worldwide use for thousands of years as the primary source of reds and oranges. The dye comes from the root of the plant, which takes several years to develop as a dye source, but when dried and ground, becomes the source of red shades that have captivated humanity for centuries.

Unlike many of the wood dyes I’ve been experimenting with, madder has more range and is also more temperamental than Logwood, Osage, Brazilwood or Cutch. After talking to several other natural dyers online during my attempts with this dye, I found that the ‘true red’ I’d seen in many catalogs, articles and books was harder to attain than I initially thought–in fact, true reds take quite a lot of patience, a steady temperature and just the right pH balance for the water and bath. 

While my dyeing approach has always been to start with the basics, I did fiddle with a few different methods for shifting the end result with madder, and I’m eager to share them with you. What I’ve outlined here feels like just beginning to scratch the surface of working with this unique dye. 

How to Naturally Dye Wool with Madder

Materials

For this dye experiment, you’ll want the following materials on hand. Remember, anything you use for natural dyeing must not be used again for food or food prep at any time, and you’ll want to store it separately to avoid any cross-contamination. 

• 1 large stainless steel or aluminum soup pot or stock pot

This should be big enough to hold 1-2, 100 g skeins of yarn, covered in water and fully submerged with room to move around.

• Dedicated tools: measuring cup, spoon for stirring, measuring spoons
• A heat source

This could be your at-home stove with good ventilation, a hot plate, a propane burner or even a crock pot. If you’d like to use an upcycled crock pot, you will not need the stock pot, but it will need to stay fully dedicated to natural dyeing as dyes are not food safe.

• A water source

Natural dyes do use a lot of water–for prepping your fibres, creating dye baths, and rinsing finished yarns. You can use rainwater if you like, especially if you find your tap water is influencing your colors negatively. You can test your water’s pH with strips and see how ‘neutral’ it is if you like as a starting point to alter colors to be warmer or cooler. How you alter these will depend on the dye you’re using. 

• A respirator or face mask

I typically would not use a respirator or face mask when moving around larger dye goods like flowers or leaves, but if you are using anything powdered–the chemicals we use to mordant, or any powdered dyes–I recommend having one on. These ultra-small particles just aren’t good to breathe in! 

• A scale that can measure grams in small quantities

If you already have a baking scale, you can use it here, just make sure not to let any dyes or materials touch the scale directly. Simply use the tare function to zero-out the weight of any vessels you’re using to measure, then clean off your scale thoroughly after use. 

• Aluminium sulfate or Aluminium Potassium Sulfate*

Mordants are chemicals that bind to both the fibre and color, acting as a bridge to attach color molecules to your wool. This chemical is the safest of a handful of options and is popular with many natural dyers. It will only bind color to protein fibres, not cellulose ones–so color taken by the wool may not be taken up the same way by any blended fibres (like cotton, hemp, linen or nylon). 

• Cream of Tartar*

Cream of Tartar adds a little softness back into your bath and prevents your wool from feeling too crunchy at the end of the dyeing process. 

• Calcium Carbonate “Chalk”

We’ll use this to shift our bath to increase alkalinity and attain deeper red tones.

• Madder powder

I’ve used a pre-prepared, ultra-fine powder for this experiment. Depending on the year, the age, quantity and source of your powders, some colors may appear differently. 

• 2 skeins of Knomad Spark

For this dye experiment, I selected Knomad Spark, a decadent 100% Organic Merino wool yarn with 219 yards per 100g hank. I chose this base for how bouncy it is and how well it takes color–I really wanted to achieve bright tones.

• Old clothes

Dye dust has a way of making it onto whatever you’re wearing and making it look dirty. Wear something you don’t love when working with any natural dyes. 

• Gloves

Rubber gloves or kitchen gloves, which can be re-used multiple times, are my preference here. While most natural dyes are perfectly safe to handle with your hands, you’ll be washing, rinsing, and in and out of water a lot, which can damage your nails and cuticles. Keep those knitting hands pretty and get some gloves. 

*These items have been pre-calculated in the amount you need for this project, dyeing 200 g of wool, however, you can also do your own calculations using the mordanting guide below. 

Step 1: Prep your fibre. Knomad pre-scours and washes their yarns before shipping them to us, so there should be no need to heavily clean the fibres–simply remove the tags, leaving all the ties, and open the hank into a big loop. Add reinforcement ties if you feel they’re necessary, and soak the fibre in warm water for an hour to get it fully saturated (typically 1 hour). 

Step 2: Measure the alum. Wearing a respirator or face mask, measure out 12% of your weight of fibre (WOF) in alum sulfate. Here’s the math for our experiment: 

200 x 0.12 = 24 g of aluminum sulfate

Hot tip: weigh out how much alum is in a tablespoon (dedicated tablespoon) and then calculate moving forward about how many tablespoons you’ll need to simplify future measuring. 

Step 3: Add hot water to your alum in a small mixing container. I like to use empty, recycle-ready plastic containers. Stir the alum and water mixture until the alum is fully dissolved and the water looks cloudy or clear, but has no visible grains in the bottom of the container. Measure out 1 tbsp of Cream of Tartar and dissolve it into the water while it’s still warm. 

Sep 4: Transfer your mordanting solution to a larger stock pot, and fill with enough water to cover your skeins of yarn (don’t add them until the pot has all the water in it). Stir and then add your yarn, moving it around to let it fully absorb the mordanting solution. Set on low heat and simmer (do not boil) for 1 hour. Allow to cool overnight with the yarn in the solution. 

Step 5: Prepare your dye solution. 

Madder can be a bit tricky. When first mixed, expect your dye solution and the resulting bath to look fairly muddy–like water mixed with clay. I found that only after rinsing the final skeins that the true color developed, like magic, in clean water. 

According to my madder source, it was recommended that I mix only 13g per 200g of fibre. However, after running an initial test, I felt that the color was not strong enough, so I elected to attempt a more concentrated bath, using 50g for the bath and just adding more water to allow for dye dispersal. If you elect to go with this “more is more” strategy, I recommend saving as much of your dye bath as possible and re-using it, as you will likely have more dye in the water than is needed for your 200g. (The recommended ratio is 50 g to 750 g according to my packaging instructions, and I intend to re-use my bath as much as possible!) 

Madder dissolves pretty easily, so mix it into warm water and then raise the temperature of the dye bath to just under boiling for 45 minutes. At this point, take the dye bath entirely off the heat and allow it to cool to the temperature of your yarn.

Step 6: Prepare the yarn. Drain the water from your yarn soak, and push a little of the extra retained water out with your fingers. Not too much–liquid being held by the fibre will help draw the dye into the yarn, so we don’t want to take it all out and risk too much splotchiness in the final fibre.

Step 7: Add your yarns gently to the dye bath, making sure that yarn has enough room to move around but is mostly submerged in the pot. If you need more water, it’s okay to add some here. Do not put your yarn back on the heat, but allow it to sit overnight.

Step 8: The next day, remove your yarns from the dye bath and smoosh out some of the extra dye–set the wool aside. Fill a sink, basin or bucket with room temperature water and add your yarn, moving it around with your hands to allow dye release. When the water is dark, drain it and do this step again. Rinse until the water is mostly clear to ensure that no dye particles will transfer to hands or clothing while working with the finished yarns. If you want, you can add a little bit of wool wash to one of these rinse baths to improve the softness and scent of your finished yarn. 

If you notice at this step that your yarn has taken more orange than red, you can modify the dye bath with calcium carbonate, also known as chalk. If you don’t have this modifier on hand, check the antacid aisle of your local pharmacy for calcium carbonate antacid tablets. Usually one or two of these crushed up is enough to modify. If you are using calcium carbonate powder from a dye supply source, you’ll need to add about 1 tsp (5 g) per 100 g of fibre, so 10 g or 2 tsp for this experiment. Mix the powder with hot water to dissolve it and add it to the dye bath, or, create a separate calcium bath and simply soak your yarns in the dye bath to transition their color to a cooler red, less orange base. 

Step 8: Hang your hanks of yarn to dry out of the direct sun (I like to use a portable hanging rack). They will drip a little bit, so if you need to dry them indoors, I suggest putting them in a bathtub or in a room with a drain (like a basement). Depending on your humidity and weather, it can take 1-2 days for yarn to fully dry, but maneuvering it so that the same part of the hank is not always hanging down can help move this process along a bit. 

I was really surprised by how temperamental madder was to work with and I’ll definitely be increasing my experiments going further. This is a dye that is especially important to keep good records on, so you can repeat the colors later, and I’ll be working through it in my dye notebook!