testing Shallot developer again tonight...
this time the ground-up shallots were soaked in water only ( no isopropyl alcohol ) for 4 days
after 30 min I removed half of the film...NO sepia tone...faint negative image
will remove the rest of the film after a few more hours
....also...instead of dumping out the ground-up shallots after draining the fluid, I put them back in the container and added 99% isopropyl alcohol...and will later test that
SO...it seems that whatever generates the sepia tone might be soluble in alcohol but not water (?!?)
the adventure continues