So what’s the “TLC” part?
The indigo is observed, tested, and tended according to which of these ingredients it needs. Empathy, rather than a prescribed solution, is the best way to help the vat recover. Take note of the vat’s condition by smelling, stirring, and looking carefully at the color and clarity. And only after thoroughly assessing what is there, offer small amounts of lime or sugar.
Stirring helps keep the indigo in reduction by activating the settled sugars, indigo and lime. Heat, depending on the room temperature, may be necessary to keep the vat in reduction. Catharine Ellis, whose blog shares her vast knowledge about troubleshooting indigo vats, keeps hers around 80F. I’ve let mine go down to 40F without a decrease in strength, and it seems that helps keep the ph level stable if I’m not tending to it daily. If I’ve been away, I heat it to 100-110F to help wake it up and encourage the reduction of the sediment, or sludge as I call the thick, dark liquid at the bottom of the bucket.
That sludge of sugar and indigo can inhibit proper dyeing. Once the vat has been observed and corrected, it must be ‘calmed’ before using. This just means, let it settle, so the solids sink back down the bottom. Then the indigo is ready to do its magic!
I’ll write more in the next post about the sludge, and how to extract and use the indigo from it.