I’ve Got The Blues

We had another record hot day on Thursday (half a degree hotter than Wednesday) but yesterday was a little more reasonable so I decided it was time to tackle the woad:

A couple of plants were starting to bolt prematurely so I chopped off all the leaves from seven plants out of the 14 total. But not that one from last year still trying to flower there on the left – it got composted instead. I’ve already got enough mature seeds from it. The rest of the harvested leaves (1800g) were washed and chopped and extraneous animal life (snails, spiders and sowbugs, oh my!) removed. Just like making a giant salad! I used the same recipe for extraction as last year from Sarah which works very well. This time I had pH testing paper so I could fine-tune how much acid or alkali I was adding. I only used about half a litre of my ever-present acid soaking solution (easier to come by in my studio than vinegar) to get it to a pH of between 4 and 5.

When I had cooled the acidic extraction pot and fished out the leaves and squeezed all the moisture I could out of them, the pot was the usual sherry wine colour. However when I added the soda ash to bring the pH up to between 9 and 10 (took about 17g) and started whisking, I could see that this vat had more suspended indigotin than any of my previous ones. Whoo-hoo! The froth was very greeny-yellow with flashes of blue which disappeared after whisking some more. After warming the pot up to 50C (120F) I used thiourea dioxide (10g) to reduce the oxygen out of the vat, adding a little more soda ash and thiox as necessary until it was a fairly clear yellow-green solution. It never cleared as well as previous vats but that’s probably because there was a lot more blue in it! 

I dyed Crossbred roving for spinning and overdyed my Alpaca Lace yarn leftovers that had previously been dyed with comfrey and coreopsis (copper mordant). My first dip was darker than any of my previous efforts though the second dip didn’t darken it as much as I had hoped. I used some fresh undyed wool roving in an exhaust dip and got the robin’s egg colour but darker than my first try last year. The alpaca skein is now really ugly and I’m not too sure what I’m going to do with it! It definitely needs help. In total I dyed about 200g in the blue vat.

After extracting the blue from the leaves, I put them in another pot and covered with water and boiled them for an hour. I removed the spent leaves which went into the compost. Then I added 10g (10% WOG) alum mordant and 4g (4% WOG) cream of tartar and entered 100g of the same Crossbred wool roving. After bringing the temperature back up to a low boil, I cooked it for an hour and then turned off the heat and left the pot overnight. As an experiment, I reserved a bit of the wool after dyeing but before leaving it overnight. The results were visibly darker the next day so it is definitely worth leaving the fibre to cool in the dyebath if at all feasible. This was an “all-in-one” dyebath because I didn’t have any already-mordanted fibre available. I got a lovely rose-beige colour from the woad leaves in a traditional boiling-water bath. Very versatile plant, hey? Not terribly strong colour though. I think the rose-beige will have to be washed in neutral detergent (Orvus or shampoo) to retain the pinkness.

Speaking of Orvus, my jar of this went totally clear and liquid down to the bottom in the heat we’ve had recently, even though it was in the basement in the coolest area of the house. I’ve never seen it do that! Usually it’s a white paste, even stiffer in winter.

So now I have 7 more woad plants obviously ripe for extracting the blue. I think I’ll do another dye morning on Monday or Tuesday, depending on the heat factor. I’d like to dye some skeins of laceweight yarn, the yummy wool and silk Zephyr. And perhaps overdye the Alpaca Lace skein again. More ugly? I don’t think that’s possible. No, you can’t see it.