Alum experiment

The lovely folks over at Natural Dye Education FB group, mostly the group’s fearless leader from Mamie’s Schoolhouse, put forth a challenge after watching a talk at the Natural Dye conference in 2020/2021 about alum not being absorbed out of the water quite as much as we think, and so clearly we had to try it. If you want to read about the results from the whole group, she has a collective blog post about it.

The premise was to use 7 identical skeins of wool, and one pot of mordant water. That water held 7% wof (weight of dry fibre) of but a single skein. So the first skein of wool into the mordant bath got a full dose of alum. Then, without topping up any alum in that pot, the next six were mordanted (and labelled!) in succession. So, in theory, we would have no alum left.. somewhere in that chain. All 7 then went into a dyepot, all at the same time, such that they would get the same dye exposure and show up where the alum stopped. So the theory went. It was left up to the dyer on what dye they wanted to use, but alum and wool were consistent for all of us.

This is not spaghetti.

I used madder (because of course I did), and had dug up some bulky weight wool yarn out of the depths of the stash, each 55g. (Except for the 2 that I mismeasured and ended up 65g. whoops.) So because my skeins were (mostly) 55g, a mere 3.85g of alum went into that giant pot of water. I kept each skein at a simmer for about an hour, and then hauled it out hot and let it cool, unrinsed. Eventually there was a giant pile of damp wool.

Cleaned out pot and and fresh water and in went 100g of madder. I had a grand plan of containing it in a little cloth bag so I didn’t have to rinse out madder dust for days, but my bag wasn’t big enough once the madder started expanding on getting wet, so that was abandoned early and I resigned myself to a million rinses later. (Dear Future Me: When you do this again, let the skeins dry after you pull them out and then whap them on the deck railing a whole lot to get most of the madder out that way. You’ll be much happier, you’re welcome.) That sat on the stove at not quite a simmer, about 70 – 80C for a couple of hours.

Top: Most Alum Bottom: Least Alum (plus bonus silk skein)

In goes all 7 skeins at once, and those got to sit around at not quite a simmer (80 – 90C) for another couple of hours before the heat got turned off and everyone went to bed. The skeins in the dyepot, and me.. well.. in bed. Next morning, rinse (and rinse and rinse and rinse and rinse) and plot what else is going in that pot of still dark red dye liquour. The exciting thing here is that in spite of there being successively less and less alum on these skeins, my 7 skeins are functionally identical. Now, madder is a dye that will take without a mordant, but not usually quite this dark and strong, so clearly more experimenting is required. (Oh /darn/, I’ll have to do more dye work. Such a tragedy. 😉 )

Well! I have more of that stash wool, so I grabbed another 600g of it, got that mordanted up (10% ish) and in it went to the same dye bath as the last batch. The madder bath was on a roll! The first 300g were still pretty solid colours, but by the last 300g I was getting pretty pale pinks and I was not in the mood to slowly simmer it down enough to bother storing it, so I called it there. Currently the big bulky wool is telling me it would like to be a stripy big thick sweater, but we’ll see how long that lasts. I’m not very good at using up the bulky yarn in my life, although I better start using up more of my dyed yarn, or I’ll be overrun!

Exhaust baths

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