As part of my homework for my Master Spinner Level 1 (through Olds College), I have to comeplete a dyer's notebook featurig 10 natural dyeing projects. All of these dye projects should feature yarns with or without alum and iron as mordants. There are lots of increadible book resourses (I picked up a copy of Modern Natural Dyeing) and website (I've been freaquenting All Natural Dyeing and Wild Colours to name a few). There is also an extremely helpful group on Ravelry (when is there not?) called Plants to Dye For, that is very active and whose members have tried every plant just about.
So Onion Skins.
I've been collecting them in a bag in my kitchen for the past two months, but after reading online that it was recommended to use a 1 to 1 dyestuffs to fibre ratio, and knowing I wanted to dye 400 grams of yarn, I got tired of doing it the slow way. So next time I did groceries I dug around the onion bin for loose skins ans filled up a bag, which they let me take home for free (after explaining to the confused cash register lady that I was going to dye some yarn with them).
I used 100g of yellow onion skins (with one red onion skin thrown it, because apparently we had one) to dye 400g of yarn.
To extract the dye: I put the onion skins in about 3.5 litres of water and brought them just to a boil, then reduced heat to a simmer for 1 hour. Then I let the whole hot stinking (it really did stink) pot rest and cool for 24 hours. I strained out the skins and had 3 litres of dye solution.
Yarn: 4 skeins of 75% superwash wool, 25% nylon sock weight yarn, bought online here.
Skein 1 and 2.
I soaked my yarn in water overnight. I poured half of my dye solution into my pot (I use a large enameled one bought on amazon, the porceline enamel surface is non reactive and this pot was cheeper than similar size stainless steel ones). And added an extra 3 litres of water. In to the pot went skeins of presoaked but not otherwise treated yarn. I brout the temperature up to just under a boil, reduced heat and simmered for 1 hour.
Skein 1: No mordant.
You'll see the without any help at all, onion skins dye wool to a lovely pale yellow with a pink cast to it. I've seen people get deaper orangey yellows with more concentrated onion skins, but at this 25% concentration (100g skins /400g yarn) the colour is definately more muted. No colour washed away with rinsing.
Skein 2: Iron after bath.
After removing skein 1 from the pot I pulled skein 2 out and hung it above the pot (did not rinse, just got it out of the water). My dyebath was still hot, I added in 1/2 tsp of ferrous sulfate powder (Iron mordant purchased from Dharma Trading Co.) and stirred it into solution. Then I lowered my skein quickly back into the pot. Bam! The colour change was immediate, with the skein darkening to a brown. The trick with an iron bath is that it is non-reversible and the colour progresses with time. I should have started with even less than 1 tsp, but alas, that's why this is a dye experiment. But after one 1 minute the skein had deepened to a lovely chocolate brown and I quickly pulled it out and rinsed it off.
There was probably enough dye materials in my pot that I could have thrown in another skein at this point, but it was late, and I didn't have any on hand to try it out. I cleaned my pot (scrub really well, the tiniest leftover iron residue can affect your colours) and got ready for Alum.
Skeins 3 and 4
These skeins needed pre-mordanting with alum. Into my pot went 4 litres of water and 2 tsp of aluminum sulfate (Alum, Jacquard brand purchased on Amazon). I added my two skeins, which had previously soaked for 1 hour in water in my sink, and heated the pot to just under a boil, then reduced heat and simmered for 1 hour. I let the pot cool and sit overnight before removing the yarn (but not rinsing it).
Skein 3: Alum premordanted
I added the second half of my dye solution to my pot, along with an extra 3 litres of water. Into the pot went my two premordanted with alum skeins of yarn. I brought the whole thing up to just below a boil, reduced the heat and let simmer for 1 hour (I know same old same old). Then I pulled out my beautiful golden yellow skein and rinsed it in the sink (no colour washed away in rinsing).
Skein 4: Alum premordanted and Iron afterbath.
Just like before, I pulled my fourth skein out of the still hot pot and hung it out of the way. This time (knowing how dark my previous iron skein turned out) I only added 1/4 tsp of iron to the pot. Stirred it up and then lowered my skein back into it all at once. Again the colour began to change immediately and although not nearly as dark. This time I let it simmer for about 5 minutes before pulling the skein. Its a yellowy brown with a slight green cast.
So there they are, four beautiful skeins, four truly distinct colours, from one batch of onion skin dye.