Im pretty new to this and sure there are corrections to be made, but I hope this helps you.....
I dont use measurements, I just eye everything.....
So I take as much spice as I want to clean up and put it into a shotglass, fill up the shotglass about 1/5 with heptane and stir stir stir (for maybe 10mins) decant off the heptaine and put that into a clean shotglass which i than put into an airtight bag
http://www.reynoldspkg.c...ns/handi_vac/en/home.asp than sit in the freezer overnight
I fill up the shotglass holding the spice again with about 1/5 shot of heptaine, this time i put it over a hot water bath (not boiling water, a few bubbles forming on the bottom is the way I go), not too long, I dont like getting it too warm because than it starts dissolving things other than spice apparently, and stir stir stir. decant heptane, put in clean shotglass, airtight bag, freezer....
Then I fill up the shotglass containing the spice again, using about 1/5 shot heptane, let it sit in the heat bath (dont let the glass touch the pan, let it be surrounded by the water, i believe the pan is way way hotter than the water) and this time, let the heptane get nice and warm, dissolve pretty much everything left in the shotglass. hopefully some brown solids will be sitting at the bottom of the shotglass, i think those are impurities and discard them.
now you should have 3 shotglasses full of spice, and the first and second shotglasses should be cleaner than the 3rd, but that doesnt mean the 3rd isnt nice though
Again I want to say, im pretty new to this and im sure some pros on here can help me clean up my technique.... but incase they dont, I really hope this helped!
Goodluck