I went thru the whole extraction process that i found on this website http://www.synchronium.net/2008/12/22/how-to-make-salvia-divinorum-extract/ at the end, i tried to dissolve the extracted material in isopropanol, and most of it dissolved, but there was chunks of material left over, could this possibly be tannin? i use about 400 ml of isopropanol and about 40 ml of water. i would think that would be enough to dissolve all of the tannin, but im not sure why there is residue left, anyone have any ideas?