You are trying to boil off the volatiles yes?
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Keep a light vacuum applied during the entire process. I would suggest using a smaller pump during the decarb (you will know CO2 is coming off because the oil will foam) to help pop the CO2 bubbles and a heavy duty roughing pump after 130C to boil off volatilizes. As always with vacuum have a cold trap and go slow. Decarbs can quickly get out of hand if your not experienced.
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The smell will always be there but you can contain it to a flask and not your entire room. Can you take a picture of the setup?
Some folks do overnight in their vac ovens…
Others 140C in an open boiling flask: How do these distillation numbers look to you? - #7 by Demontrich
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Not quite. There are no volatiles left after the stuff is held at that temperature for a while. New volatiles are formed with each increase in temperature. When I start SPD I can set it to 160c and it will gas for a couple of hours, then stop and vacuum will settle below 100 micron. If I then increase to 160c I need to wait an hour or more before it stops gassing at that temp and vacuum settles again. It gets the worst at around 180-190c where it will take several hours to stop gassing. This is also when it produces some water and some specks in the liquid that look like burnt protein. The water obviously gets pulled off fairly quickly, but the specks happen at the same time the burning smell starts.
The same process has been used for THC strains without this problem.
As for bromocresol green I presume this is to test for presence of the acid forms? Lab tests show there is no acid forms left.
Yes, bromocresol is to confirm decarb. Lab tests are expensive…and take days.
Or do you already have In House analytics ?
What do you have for a vac pump? (CFM?)
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Franz, how long would you recommend at 130c?
Just wondering because I’ve had it in the SPD vacuum set up for hours at 130, 140, 150, etc.
And yes, I use a small cheap pump for pulling the volatiles off before I switch over to the distillation pump.
Potency of your crude?
Thanks for the bromocresol trick. I will definitely get this, but my point was that I already had these samples lab analysed. It’s been frustrating me for a couple of months now.
Edwards RV12. Like I said, I can do my second run at about 50 micron all the way through, so i don’t think it is my pump or kit that’s the problem
45% cannabinoids on the winterized extract.
Wow!! That seems extremely low. My guess would be that this is your primary issue. Feeding at 70+% cannabinoids is more traditional.
what is your input potency when you successfully use this protocol for THC crude?
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How do you get 70% in crude if the plants are only 5%? I know 70+% is standard for THC strains, but surely not for hemp. We are limited to 0.4% THC in our hemp and our strains are about 10:1 (with a bit of luck and heavy trimming maybe 15:1). So getting 4-5% in biomass is standard.
I can get 55% crude, before winterizing, from fan leaves. Which run less than 3% thc.
Your current winterization seems insufficient. -20 at 10:1 will not get the job done.
Colder. Less ethanol. Or try methanol.
What is the proof on your ethanol? Do you use a proofing gauge on your recovered solvent. If you’re not returning to 190 every time you won’t have good results.
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I just want to point again to the my comment #2 in original post. A heptane extract of the same material treated exactly the same in every other way did not cause the gassing problem. So I would have thought that it is not a decarb issue nor a kit issue. It’s something in the extract that does not get pulled out by heptane, but does get pulled out by isopropyl.
I have also tried to dissolve the isopropyl resin in heptane to see if anything does not dissolve, but that didn’t work as indeed a lot of stuff didn’t dissolve and just bound up the goodies.
How long are you soaking? What temp? Water content in iso?
For 70% unwinterized crude from 10% biomass, I extract for 5-8min at -50C. That was getting me 85% of the cannabinoids last time I checked.
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Can try methanol, thanks.
My ethanol is top food grade 96% (>190 proof). I have not reused any so as not to introduce variables. But I am also a distiller so accurate recovery won’t be an issue in the future 
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How about your primary extraction solvent and extraction parameters (as you believe it’s the extract that’s the issue)
How about trying it without the steam distillation step up front?
(My understanding was that CBG strains had minimal terps anyway)
cold extraction only gave me about 1/3rd of what’s in the biomass. A few hemp growers tried this here because it worked so well on THC strains and failed badly. Even at RT it needed a second extraction to get about 90% out. So yes, I am aware this pulls out a LOT more gunk and that’s probably what’s causing the problems. I was hoping someone here might have encountered this problem and found a process to remove the offending ingredient.
Not sure if hemp is different to THC strains in this regard because heptane extraction also only pulled about 60% despite a 24h soak, while it pulls nearly everything on THC strains. I’ve become very cautious about applying THC processes to hemp
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Yeah, folks around these parts generally won’t touch biomass below 10 or even 12%.
Are the terpenes worth the trouble from this strain?!?
Are those numbers based on input vs output? Or do you also have coas on the spent material?
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