Indigo fructose vat

I am determined to learn to use Michel Garcia’s fructose indigo vat rather than the very simple but clearly toxic and stinky hydrosulphite vat. I am also on a mission to create handspun, plant dyed yarns for colourwork, and I have a pattern in mind which requires some greens.  Also a plan about sock yarn in which this previously undyed, now (osage orange yellow) skein of BFL/silk becomes a variegated green.

2015-06-08 15.20.47

I prepared the vat and waited for a bronze sheen and yellow-green liquid below as signs reduction (the removal of oxygen from the vat) had been achieved.  I have a Ph meter to ensure the Ph is within range.

2015-06-08 10.49.33

I had success with reducing the vat but a lot of difficulty in getting the Ph into a range suitable for wool.  In the end, I decided to make the most of it and dipped my ugly cotton bags several times.

2015-06-08 11.08.43

In all I dipped them three times and they are now an old denim colour which is a decided improvement.

2015-06-23 09.22.05

Once I had managed the Ph, next came fleece from Viola, previously dyed in coreopsis or osage orange.

2015-06-08 14.33.07

Finally, in went the gloriously yellow sock yarn.  That yellow was so awesome I was tempted to leave it as it stood.  But I was looking for yellows and various shades of green, and here they are, ready for the next stage of my cunning plan….

2015-06-16 08.56.59



Filed under Natural dyeing

10 responses to “Indigo fructose vat

  1. Susan

    hA, you are reading my mind! However, with this wild puppy I may have to back off on some of my plans. you did a great job, thanks for showing us. I understand the reluctance to dye the yellow……..


  2. purplejulian

    how exciting! you have a meter for the ph – I need one of those, litmus paper is no good, it goes dark blue of course! I always find something in cotton to dye first, as wool or cashmere is my staple to dye but it’s always to alkaline when you wake it up with the lime. now you have your vat it should last for ever, Michel says freshen it up with a stronger mix of the same thing (ie less fluid) when the colour starts to weaken. I moved mine into a bigger container twice, now it’s in a big plastic dustbin suspended by its handles in a bain marie effect steel drum over a heating element, for dyeing wool it has to be between 40 and 50 C. he is coming back to Scotland at some point next year, to the Big Hat textile centre in Newburgh. I’m definitely going to join up for that.


    • The Ph meter is a great help. I requested it as a birthday gift and Dad bought it on ebay! I have kept this vat, so I am ready to try seeing if I can keep it happy. I need to keep thinking about how to manage temperature….

      Liked by 1 person

      • purplejulian

        it took me several tries to find the right thing, based on Michel’s recommendation of a bain marie. it depends on the size of your vat, I ended up with a big dustbin impossible to lift, so it has to stay in the water container. a friend got herself a water boiler, the sort for making industrial quantities of tea, and kept her vat in it, heating cautiously, but the last time she used it it stopped working and she thought she got water in it where it shouldn’t be … (I actually use one of those for dyeing, so far it’s been great, and my electricity is bought from a renewables provider so all totally eco!) you could get a thing, I’ve forgotten the name, to sit a saucepan on inside another saucepan, and basically Michel said to have a plastic bucket or bin sitting in hot water inside some sort of metal container that can be heated directly. I know India does it with a direct gentle twig flame on what looks like a pretty massive oil drum, (but maybe that’s a bain marie too, she didn’t say) you certainly need the temp, even for silk and cotton/linen this type of vat will not work happily cold. though actually when Michel made it in Scotland we used it hot the first day, and then cool the second … but it does seem only to be reliable when warm in most people’s experience. I suppose it needs the heat for the chemical reactions going on.


      • I have taken to using direct heat and having the vat in one of my dye pots. I warm it up gently and then park it in a milk crate lined with a woolen dog blanket to keep the heat in. Not that this is the best possible arrangement, but it is the one I can make work at present! I have the vat sitting dormant in a bucket with a lid at the moment and will be trying to figure out whether I can find a way to get that into a bigger vessel that I can realistically heat, or whether I will have to pour it into a dye pot to warm it up when the time comes. I don’t dye with indigo regularly and need to give serious consideration to what would make it simplest without tying up resources that could be used for other things. It may be I’ll put that bucket into a bigger container in the summer sun and treat indigo as a summer dye.

        Liked by 1 person

  3. as you say the trick is to dye linens and cottons first…which will reduce the pH through the introduction of a little oxygen each time they go in. then silk, then wool. there’s a trick to wool too, that i discovered in my experimenting/play. if you steam it before dipping then the fibres open up and those wee scales lift a bit and you’ll get a much better dye takeup


    • purplejulian

      Oh yes, that’s a very good idea, and I seem to remember Michel telling us to wet wool in warm/hot water before putting it in the vat, but of course if the vat is already at 40 – 50 C that makes sense to prevent thermal shock and shrinking, so I do that, and try to keep it warm between dips too. I think that because of the scales wool actually takes indigo better, and keeps it better than cotton and silk, but that’s only for me with my very short experience of only one kind of indigo vat
      Vivienne Prideaux passed on another tip; she doesn’t rinse between dips, but uses an old spin-dryer to get the liquid out, then airs the fabric. I tried this, and it saves hugely on water, plus the liquid extracted can go straight back in the vat, undilute, when you have finished dyeing and can de-oxygenate/reduce the vat again.


    • Thanks so much… These are logical reasons to do what I only stumbled on. I prefer to understand when I can organise it! 🙂


Please feel free to join the conversation...

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s