Singing the Blues

 I started the Japanese Indigo seeds in February, in hopes of getting some seed.  I planted it in the garden a bit early, putting it under plastic cloches from the dollar store.   I planted a couple of plants without the cloches to see what difference they really made.   The Indigo plants under the cloches were definitely happier, with more growth, larger, and noticeably more lush.   This enabled me to do a small dye vat the other day.   I cut 550 g of leaves and stems.   I took some of the leaves from the stems, but I'm not horribly careful about it.  It's a lot of extra work and I don't think it makes a lot of difference.

I set up a double boiler system with my dye pots, putting some water in the larger one and then setting the smaller one inside it.   This makes it much easier to keep the Indigo leaves from getting to hot.    I put the leaves in the pot and filled it with lukewarm water.   I use a candy thermometer to keep an eye of the temperature.   It needs to cook for about 2 hours, getting up to about 160° F, and no higher than 180° F.

Every once in a while, I stir and squish the leaves  to make sure every one of them gets time covered in the hot water.    It's also important to keep an eye on the water level in the larger pot, to make sure the water level doesn't drop too low.

When the temperature gets warm enough and is there for a bit, the leaves start to look a bit wilted and a scum forms on the top.   This is a good thing as you know the pigment is being released.  The scum is a brownish colour, sometimes with a bit of blue or green in it.

When the 2 hours of cooking time is up, it's time to drain the leaves into another pot.   Using rubber gloves, squeeze the hot leaves to get as much of the brown liquid as possible.  They are really hot, so I take very small handfuls, which are easier to squeeze out anyway.    The remaining leaves can be boiled up for a second colour, but I`ve only ever done that with Woad leaves.  Because the Japanese Indigo has so much more pigment, I`m usually ready to clean up when I`m done with dyeing blue.

Anyway, take the brown liquid and add some soda ash or baking soda.  You can also use ammonia, but it smells.  Baking soda works just fine.   Then you need to aerate the liquid by either pouring it back and forth between two buckets, or I use a dedicated stick blender.  It`s permanently dyed blue, so easy to know it`s not for blending foods.

When I`ve aerated the liquid from Woad plants, I usually get little specs of dark blue sitting on top of the foam.  With the Japanese Indigo, the foam often just goes a pale blue, greenish colour.

The final step is to add a reducing agent.  I use Thiourea Dioxide (Thiox).   It`s neat to watch the foam break down and disappear almost immediately after adding the chemical.  You can use spectralite as well, but thiox is available more readily around here.

You need to let the vat sit for a while while the air is worked out of the vat.  A metallic looking scum will form on the top and the vat will turn green or greenish brown when ready.

I had put some fibre in a tub to soak part way through the initial heating time, so it had been soaking for over an hour.   I put it in the vat, let it sit for a few minutes and then pulled it out, carefully squeezing out the excess liquid near water line, just as the fibre came out of the dye.  This supposedly helps eliminate excess oxygen getting into the vat.  

It comes out green and as the air hits it, it starts to turn blue.   If you want darker colours, you need to use multiple dips with airing time in between each dip.

Eventually, I ran out of fibre and the vat was giving lighter blues, taking several dips to get to where I wanted the colour.    Indigo doesn`t need a mordant.  Although it is a little bit of a fussy process, it`s fairly simple if you follow the steps put out in most of the natural dyeing books.  I like Rita Buchannans  A Dyer`s Garden.   Look at the pretty blues!