The dispensary owner who had my stuff tested when it scored 91% total cannabinoid told me that all the yellow extract he comes across averages about 60% total cannabinoids. He gave me some very pretty stuff in comparison to the dark red extract he had obtained from me in bulk. When I hit that stuff from a titanium nail, I realized it was seriously under purged from the harshness and heat from the hit. So I pulled out a glass vial, heated it w a lighter and we seen the activity that butanes know for, little bubbles everywhere. I told him to purge the batch in acetone noting the weights before and after. The excess was going to be a complaint for the extractor to vacuum purge longer and perhaps at a higher temperature if 104F was observed. Then maybe 80% or better could be achieved, but it was largely butane diluting the extract giving a larger percentage of residual solvent.
