so i promised last time that i would detail out how i made the natural fermentation vat that we used at our dyeing party last week. the recipe i used comes from cheryl kolander at aurora silk and you can find it right here. there is also a very similar recipe in "the art and craft of natural dyeing" by jim liles, which is one of my two natural dye bibles that i refer to all the time. he has several indigo recipes, including old fashioned sig vats, which use just indigo and urine. but i am nowhere near that hardcore. and my vats are already stinky enough, thank you very much.
in any case, as i said, the recipe is very simple. for my medium sized vat, which i did in a big stock pot (holds around 2 gallons, or 7-8 litres) i combined:
warm water, almost to the brim
50 grams of finely ground indigo
28 grams finely ground madder root
28 grams regular old wheat bran
170 grams soda ash
stir very well (especially when you add the indigo - it is notoriously tough to dissolve), put a lid on it (important, as the point is that you're trying to reduce the oxygen out of the vat), and put in a warm place.
and that's it! the key is that you have to look after it a little bit, but all this means is that you need to stir it once a day (quite well), and make sure it stays warm. as i said, when i did this vat in the winter, it took almost 6 weeks to be ready to dye, but the vat that i started recently and have been keeping in a warm attic only took 5 or 6 days.
gotta run to teach a class at the workroom (felting this time!), but i'll come back in a day or two and talk about how you know that your vat is ready to dye.
any questions so far?