Indigo First Harvest 2020: Step 3
I put a straining cloth over my aeration tank (mosquito netting) to catch the majority of leftover debris.
I will strain it even more later.
For the quantity of indigo I process, I have several 100-gallon horse troughs from the local farm store.
Now it's time to add some hydrated (slaked) lime, and oxidize the indigo with a lot of agitation.
A video of adding lime to the tank, and the start of aerating the indigo:
As the water turns blue, I check in from time to time to see if the indigo is turning blue and beginning to sink.
|This is what the water looks like before adding lime...
And this is what it looks like after lime and aeration.
If it's still a little green, add a little more lime and keep agitating!
When you let it sit for 5 minutes or so, you will see that the indigo sinks to the bottom.
Before and after
Very blue! I now have the indigo pigment we will save for dyeing later.
It's hard to tell from this image, but once enough lime is added and you've aerated long enough, you can see the swirls of indigo.
The trick is, the more lime you add to the indigo, the more lime you will have in your final product.
If you're trying to produce a darker, more pure indigo, then make sure to add lime more slowly, check the pH more carefully and give it plenty of time to settle before deciding to add more lime.
THE FINAL STEPS! Straining your indigo for storage...