Saltpeter 1 (human urine)

I gathered

• 4.4L of peat moss
• 4.4L of pumice pea-gravel
• 2L of urine
• 2L of water
• 2 ceramic garden boxes

I put a 50/50 mix of moss and pumice in each garden box
I poured 1L of urine into one of the boxes, and 1L of water into the other, and labelled them
Conditions are warm and dry outside

Day 1

Day 2:

• Both are "wet"
• Conditions remain warm and dry
• Turned the containers

Day 3:
Both are "damp".

• I added 1L of urine and 1L of water to the respective boxes
• This was a mistake. This was far more than the urine box could absorb, leaving a pool atop the moss
• I turned everything

Day 3

Day 5:

• Still small pool in urine box
• I removed 1/3 of the "water" moss/gravel mix and put it in the "urine" side
• Turned everything

Day 6-10

• Turned every other day or so

Day 12:

• Everything dry
• Added another liter to both containers

Day 13:

• Turned earth.
• It's obvious now why they called it 'black earth'... even when dry it's much darker than the watered soil

Day 16

• May have observed the "white crust/crystals" mentioned in some texts
• Almost completely dry, no odor whatsoever
• Added another (4th) liter of urine, making it very wet... not quite pooling.

Day 17:

• Turned earth, very very wet. Maybe need to switch to 5 day cycle?

Day 18:

• Ditto. Looks like we need to slow down delivery. 

Postmortem
It appears that the timing (20-ish days) was short but reasonable, that the aeration was reasonable, but the carbon content may have been too low, and the containers neither large nor sufficiently insulative enough to maintain the required temperatures for rapid decomposition. Future tries should:

1. Scale up the carbon content (sawdust, straw, etc)
2. Add all the urine at once
3. Make some concession to keeping the mass temperature high.