Dyeing Yarn with Silver Birch Bark in a Long Colour Change

Not long til we go to Somerset for Spinning Camp. So much to look forward to, not least the promise of a turn at weaving a shawl on a friend's seven foot triloom. In preparation, I went digging through my stash, searching for 400 metres of double knitting wool. The skeins of Coburg Fuchschaf sheepswool yarn which I bought last year in Berlin feel more durable and strong than smoochy soft, but I'd been advised to choose some wool on the tougher side, as fulling a woven shawl will improve the handle of the final fabric. 

Such expert advice is one of the many joys of the company of spinners. Apparently, the best effects in triloom weaving come from using a long colour change yarn. Though there may well be better ways of setting yourself up to do this, before scouring and dyeing the yarn, I wrapped each of my 200m skeins round the top of a clothes horse, making between 10 and 20 turns and tying a marker of scrap yarn around them, before moving down to a lower point, wrapping another set of turns, tying a marker, moving down to the lowest point, wrapping and tying, then coming back up and down again, making more bundles at each of the three points til the yarn ran out. Each of my three sections ended up with several sets of wrapped turns, linked by short trails of loose yarn. The three sections were secured individually with loose cotton ties in four places. Clouds of lanolin floated out from the yarn during a hot soak with detergent. Given the awkwardness of transferring each triple bundle of yarn, trying not to twist up the lengths of yarn running between the sections, I was grateful I had made up a pot of bark dye, so the wool would not need to be mordanted.

Four hundred grammes of freshly peeled silver birch bark had had a week to soak in a pot of water and then been simmered for an hour or two and left overnight to cool before being sieved out. The natural pH of the resultant dye bath was slightly acidic. Adding some soda ash to alkalinise a test sample in a jam jar made the colour look deeper and redder, so I brought the whole dye bath up just above neutral. I'd like to have made it properly alkaline, but feared a high pH might make the yarn weak and too rough to be redeemed by any amount of fulling.

The two skeins, with their complicated sets of ties, in total measuring 400m and weighing 200g, were launched sopping wet into the dye pot and simmered en masse. The first time I tried silver birch bark dye, the outcome was a pale pink and I blamed the nature of the wool for the poor uptake of colour. This Coburg Fuchschaf yarn started out a goldish cream colour and had only turned palest orangey pink in the first hour of simmering, despite having twice the weight ratio of birch bark as my my first attempt. Damn, damn, damn. What the hell, this time, I turned up the heat a little and gave it another hour, which did deepen the colour considerably. The wool had become impressively red after four hours, when I turned off the gas and left it to cool overnight.

Now to dye the long colour change sections in different shades. Adding dissolved iron to one pot of water and dissolved copper to another, I managed to separate each of the skeins into its three constituent bundles and land one in the copper pot, the next in the iron, keeping the third just as it was. After heating them for half an hour, I wanted to rinse out the copper and iron as soon as the skeins were cool enough to handle. This became a total logistic nightmare of shuffling the linked hot pots towards the sink, rinsing sections separately in order not the cross contaminate the colours.

Once dried, I could compare the silver birch dye results with my previous efforts. The deeper colours may well be due to prolonged heat. On the left is the unmodified pinky orange, in the middle, the saddened brown of iron modification and on the right, I think the best result, with copper adding a purple cast to the pink.

It took nearly an hour to wind each skein into a ball, undoing the ties on the main three sections then working back through each set of wraps, saying to myself 'Patience is a virtue.', knowing full well that being methodical was the only way to avoid a rats' nest of yarn. I do look forward to seeing the effect of weaving it on the triloom, though the shawl is going to have to be pretty spectacular to persuade me to dye yarn in a long colour change again. Thinking about it now, it would be more straightforward to dye fibre, then spin the colours in different lengths. I used the remaining silver birch bath to dye a silk scarf in a contact dye bundle. The pinky red came out beautifully on silk and though the garden dye plants are still juvenile, their leaves are already giving out some colour. Here's hoping the sun will shine in June, on plants and campers alike.