Friday, 17 September 2010

Analyzing Dyer's Knotweed Experiments

I've been thinking about the Dyer's Knotweed vats using the stainless steel pot as a double boiler as opposed to the canning jars in a stainless pot as a double boiler. In the first instance it was a small pot inside a larger one. The small pot balanced nicely because the handles fit on the rim of the larger of the larger pot. I had filled the small pot, not that small because it is an 8 quart pot, with leaves, covered them with water and then covered the small pot with tin foil because the lid wasn't handy. The canning jar double boiler had 3 canning jars because they are heat resistant and stronger glass than regular jars using the same pots.

The difference I could see after the fact was that while the leaves seemed to be packed into the stainless pot, the canning jars were much more firmly packed. Because of the way the rims of canning jars are, the leaves were held under the water more easily and there was definitely less surface area of the water exposed to oxygen. The stainless pot measured 8 litres but the canning jars were simply 3, 1 litre jars. While I don't know for certain, I think that the less air exposure was probably a big factor. As well, I wonder if it was easier to keep the temperature steady and high enough in the smaller canning jars than the larger stainless pot. I had a thermometer in the water vessel each time and with the canning jars, there was virtually no fiddling with the heat source temperatures compared to the stainless pot experiment.

Since the rest of my procedure was the exact same and the only differences were in which vessel I chose to heat the leaves in the first place, I can only think that it was the mitigating factor in the colour or lack thereof. Considering there were two vats in using each method and each time the 8 litre pot rendered less colour than the canning jars, I'm only going to use the canning jars from now on.

I redid the canning jar experiment the next day. I again got lots of colour and ended up letting the vat go because it was just too late in the evening for me to keep it up. I ran out of the white rovings I'd been using and put in some blue I'd dyed with indigo earlier this summer, thinking it might add a tad more colour to it. Instead it turned it greenish.. I totally wasn't expecting that!

There is much more Dyer's Knotweed to use. I've 1/2 lb of off white Bluefaced Leicester rovings that I can use and then I'm stuck with using white fleeces for the rest of this.


Sharon said...

I looked Dyer's Knotweed online and see that is has very similar behaviors to indigo. I bought the freeze-dried indigo and was disappointed that the blue wasn't deeper. It appears to be pretty temperamental to grow~

Helen said...

Thank you
Your thoughts make a lot of sense if you see what I mean. Thanks for posting.

Karen said...

If you're running out of wool and time.... I'd be happy to take some of the Dyers Knotweed off your hands. :)

Though I guess we aren't predictably seeing each other again for another 2 weeks. Oh well.