Seven pounds of leaves and stems were cut and placed into a 32 quart, stainless steel pot.
Harvest - 5 of 6.jpg
Water is added up to the lip, covering all the leaves. A rock is placed on top of all the leaves and a lid is placed on top to let the leaves soak
Fresh Leaf Indigo Dye - Fresh Leaves in Water.jpg
After one day of soaking (at approximately an average temerature of 62° farenheit) the standing liquid takes on a tinge of blue/green and appears slightly iridescent. Presumably, higher temperatures would speed this necessary decomposition.
Fresh Leaf Indigo Dye - Leaves Soaking Second Day.jpg
At this time, the leaves are limp but still seem to maintain all their color.
Fresh Leaf Indigo Dye - Indican forming.jpg
After two more days, the leaves feel thin and tear easily, like slippery wet paper, when rubbed between the fingers. The standing liquid is a blue-green with dark blue and purple bubbles at the top. The liquid feels viscous.
Fresh Leaf Indigo Dye - Soak Leaves Day Three.jpg
The indican rich liquid was decanted into another vessel of the same volume to be processed into indigo.
The top layer of leaves are mostly green, but the rest of the fully submerged leaves (more than an inch from the surface of the liquid) appear yellow and spent. These are discarded and composted.
Fresh Leaf Indigo Dye - Spent Leaves.jpg
The color of the liquid is nearly opalescent, transparent, turquoise green
Fresh Leaf Indigo Dye - Indigo Decanted liquid.jpg
This liquid is then combined with 1/4 Cup (for 6 Gallons of pigment rich liquid) slaked lime and blended intermittently. This time-lapse video shows the periods of blending, which lasted for about a minute each, followed by 5 minutes of rest. This blend/rest was repeated over the course of an hour until the liquid was a saturated, opaque indigo. The tool used was an immersion blender which is very effective at whisking in air to the mixture, but any simple whisk that can effectively make bubbles would work.

The soaked plant extract and the indigo sit side by side, exemplifying the before and after of the indigo extraction process. The indigo rich pigment on the right could be allowed to sit overnight and the pigment would settle to the bottom of the container. Alternatively, the dyers choice of alkali and reducing agent could be added to turn the indigo pigment to indoxyl and create an active dye vat.
Indican Rich Liquid and Indigo.jpg
Here, a decanted portion of the indigo liquid was used to make a starter solution for a vat. Into this one quart jar was added 100g of ferrous sulfate heptahydrate (Iron) and 150g of calcium hydroxide (Hydrated Lime). These two additions work in concert with each other to reduce the indigo and make it suitable for dyeing. This was blended together and allowed to sit for two hours at room temperature before being added back into the larger (six gallons or so) stainless steel vat containing the remainder of the indigo extract liquid.

Fresh Leaf Indigo Dye - Indigotin Suspended in Water plus Ferrous Sulfate and Hydrated Lime.jpg
The iron (added just before the video started rolling) and the lime combine to reduce the indigo present in the starter solution turning the liquid green. This stock was then covered and let rest for a couple hours before being added back into the large vessel of indigo liquid.

The vat conditions were sampled about an hour after the stock solution had been added to it. The vat color is green-blue-green and the bubbles are blue which indicates that the vat is under-reduced and will not effectively transfer much pigment to the material. Ideally the vat will appear yellow-green and have a purple coppery skin and bubbles atop. Despite my impatience, the vat yielded a beautiful pale blue after rinsing the sediment.

This vat was the left to rest and develop for 24 hours, at which time it had reduced fully and yielded very dark shades of blue with only a few dips.
This indigo plant was crowned with a scarf dyed from its own color.
Indigo Persicaria Tinctoria Blue Dye Extract Dyed from This Plant.jpg