Though I know silver birch bark contains enough colour to dye an equal weight of fibre, I prefer to start with twice as much bark, so as to be sure of a deep pink result. After peeling 600g bark off a fallen birch branch, I planned to dye 300g yarn. The peelings were left to ferment for a week in a bucket of water, then simmered for an hour or so and left overnight. The process of fermentation had reduced the pH of the dye bath to a fairly acidic pH 5, so I added enough dissolved soda ash to bring it up to neutral pH 7 before simmering my scoured yarn for an hour. After soaking overnight, the yarn came out a nice deep pink and the dye bath was still so dark I could barely see the peeled bark floating around at the bottom of the pot. Retesting with indicator paper later that day, it seemed that the bark must still be fermenting despite having been simmered, as the pH had dropped again. Over the next five days, I kept adding a little more soda ash to keep the pH neutral and dyeing successive batches of scoured yarn by simmering for an hour and leaving them in the pot for an overnight soak. By the time the dye bath was giving only palest pink, the original 600g bark had dyed 1.4 kg of fibres - some of them shown in the photo above.
I've used the inner bark only to give deeper hues.
ReplyDeleteFantastic colours
How did you separate the inner bark from the outer? For me birch bark is a stubborn material.
DeleteI've never tried peeling off the silvery skin - I suppose chopping it up small would expose as much of the underlayer as possible, but since peelings are quite thin, I'd have thought the water and heat would soak them through and extract most of their dye, even with the outer skin left on. I might try a comparison to see what happens.
Deleteunfortunately birches are uncommon here, ours in the garden is a stick with 5 leaves at the top:( not much bark to be had so - but it looks like it's really worth dyeing with!
ReplyDeleteI'm lucky there are so many silver birches here and not a winter goes by without a good few trees falling. I've tried various other trees, as and when available, but I reckon silver birch best repays the time spent.
DeleteHe-he, a stick with five leaves on top!
ReplyDeleteWhere I live, on the contrary, birches are very common but I havent got any acceptable colour from them as yet, despite quite a few attempts. Will try again, following your procedure.
Do let me know how you got on. I was reading a post by rihiivilla who recommended lots of alkali to fix the dye - I haven't had trouble with it washing out, in fact, silver birch has been very fast for me, I just let the yarn sit for a week before rinsing. It didn't take very well on Cheviot wool, but I've found the pink takes fine on other British sheep breeds, merino, silk cotton and linen. Perhaps she has a different species of birch - I'm using Betula pendula
Delete"let the yarn sit for a week before rinsing"
DeleteDo you let it sit in the dye bath or you take it out of the bath and rinse it only after a week has elapsed?
I take the fibre out of the dye bath, squeeze out most of the fluid and hang it to dry. A week later, I give the half an hour to soak in plain warm water, then change the water a couple of times until the rinse water looks clear. Squeeze out the water, dry again and keep in a bag til I want to knit it :)
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