We typically yield 18/25%, depending on raw material, and tell how we are doing by examining the spent material afterwards with a 100X microscope for intact trichome heads. Only the stalk should be left behind.
Check E-bay for cheeep hand held and UBS microscopes.
I'll check that out thanks!
If you had 24% potential and yielded 16%, I would say you have some opportunity for improvement.
That's what I was thinking, hopefully next time I can get it better.
Beyond the mention of 5 cans of butane, you made no mention of process or equipment, soooo shall I infer you are open blasting???????????????
Open blasting, 1x 50 micron screen and 2 coffee filters. 15in glass extractor tube.
5 Cans (size?) for 70 grams is excessive open blasting. What diameter tube????????????
I used 5 cans of "Puretane" (10.14 fl OZ each).
How are you preparing and packing the material?
Broke big nugs into "popcorn" size nugs and shoved it in the glass tube. I notice if I grind my material it turns my oil green.... I may have packed it to tight, could this cause issues on yield?
What temperature is the material column and what temperature is the butane?
I stick the empty glass extractor in the freezer for a bit, so it keeps its liquid state longer when I blast. I leave my butane cans outside to keep them cold.
What vacuum levels are you running your oven.
29 Hg
Pull and snap can be soft for several reasons, one of which is retained solvent. Others are high monoterpene content, partial decarboxylation, or high plant wax content.
After I winterized my bho it makes it more of a "shatter" material, I'm assuming because I stripped the plant wax and maybe any possible solvents.
FDA lists n- and Isobutane as GRAS, or generally regarded as safe.
https://www.gpo.gov/fdsys/pkg/CFR-2012-title21-vol3/pdf/CFR-2012-title21-vol3-sec184-1165.pdf
FDA residual solvent standards for Class III solvents, allow <50mg/day maximum or 5000 ppm. Some locals have set the limits for dispensary products at 10% of that, or 50ppm.
They use it as a food propellant, for things like whipped cream, to put things in prospective, despite the abounding hysteria that sometimes surrounds butane residuals on forums.
If you are open blasting from cans, the question of mystery oil rears its ugly head. You didn't mention what brand you used, but here is some reference material:
https://skunkpharmresearch.com/bho-mystery-oil/ I used http://puretane.ca/index.php?route=common/home. 9 times filtered
Mystery oil is primarily longer chain hydrocarbon molecules, with higher boiling points, so they are easy to remove before hand using fractional distillation, but difficult to remove after extraction, without degrading the concentrate.
Both Hexane and Pentane are typically present in mystery oil, which are also simple fully saturated alkanes and relatively non toxic as well, but our livers turn them into 2.5 Diones, which are carcinogenic.
ASSuming one of the cleaner brands of "reagent grade" cigar lighter butane's, mystery oil levels are typically below regulated limits, so no reason to run yelling the sky is falling, but reason to pre-distill LPG to remove it before extraction.
Another is taste. Human threshold sensory perceptions for HC's are typically in the low PPM to high PPB levels, so mystery oil does add a butyl undertone.
Soooo, my best guess auguring the bones and chicken guts from here, is that you are probably below maximums, but the way you typically tell for sure is through GC head space sampling, which I suggest you have done, to dial in your process.