Unfortunately this formula will not work. You are not taking into consideration that ALL thc will not be extracted...and a portion of your 15% example WILL be plant matter, a big portion. When I first got into making hash I mistakenly thought the 25micron was the best, however the 73-90 micron is the best for quality. BTW, I use an 8bag set made by "Bubblebag", made probably 100 runs over the years, and have only been able to hit 54% with standard methods. I really need to know your secret.
Only a solvent extraction will recover near 100% of THC and THCA ... but a good extraction will do that: 99.9+%.
Back in the day I had a batch of trim that I ran through bubble bags. I ground thtrim lightly for homogeneity, then extracted a portion down to bho-equivalent (a different but comparable hydrocarbon solvent was used for Soxhlet extraction). The extract was weighed. It was then refined to recover pure THC, which was also weighed. The heat-treated extract was ~85% by weight THC.
I bubbled the remainder of the shake. The recovery of trichomes was well short (about 2/3 of theory iirc) of what it could have been. The 150-micron fraction, the prettiest and heaviest, assayed at approx. 80% THC (after heat treatment) by gravimetry.
Full-melt bubble is a delicious clean smoke. As a recovery freak however I like extract, which when done the right way exceeds bubble in purity, equals (yes, subjective opinion) it in flavor, and gives the satisfaction of getting all the goods and ditching all the lawn clippings.
For me to tool up to the point where I could re-run THC by weight assay, i'd need to assemble a rather ambitious and expensive lab. That I won't do. cn
cn
