Originally Posted by hearmenow

Apparently THC is water soluble, while chorophyl and the rest of the vegetation and chems are not. The THC is dissolved in the alchohol and passes through your strainer or filter. The rest of the plant is caught in the filter. You let the alcohol evaporate and that leaves you with the THC in the form of a paste. Of course, there is still other foreign matter that doesn't get filtered out but most of the junk is already removed.