This is a large straining frame. For the amount of indigo I am processing, I found it necessary to have a larger straining surface. This is just scrap wood made into a frame, with some window screen stapled to the bottom.
I've also just clamped fabric to the top of a bucket or barrel for straining, which works just as well.
The fabric is a heavy synthetic dress fabric from JoAnn Fabrics. It's thick enough that one layer will keep the indigo from falling through.
|I rinse the indigo off the fabric in a couple buckets of fresh water. I use as many buckets of clean water as it takes to get all the indigo off the fabric.|
I use two layers of the window sheer fabric; it seems to help catch extra grit if there's two layers.
I make sure I have a bucket/trash can large enough to add extra water as I am rinsing everything out.
|I pour the indigo I just washed off the fabric through this mesh.|
|Once this is done, I use more fresh water to rinse the indigo stuck to the fabric and sludge.|
|What was left behind. This is just plant matter and grit I can toss back into the garden.|
|I don't really have a measurement, I just add a few glugs of vinegar in and let it sit 15 minutes. This is a bit like removing calcium deposits from household faucets and appliances. In this case I'm neutralizing excess lime (aka calcium hydroxide or calx) from the indigo.|
Straining again after the second rinse.
|Last year, I strained my indigo over a barrel and collected the paste.|
|This year, I am drying the indigo out to store as powder.|
|Keeping in mind that this is the first cutting, I know that subsequent cuttings will produce a lot more indigo.|
Refrigerated indigo will last a long time, a year or so (I have some that's over a year old). However, if you keep it long enough you may find yourself scraping mold off from time to time (you can still use moldy indigo for a dye vat, just scrape excess mold off).