Couple passes on spd takes care of that in my experience. Would you agree?
1 Like
haven’t distilled THC in a while. doesn’t seem to be as big an issue with CBD
Last time I tried removing that stench (from someone else’s first pass thc), a second pass alone did not solve it.
I reuse ethanol all the time, but i only winterize first pass after removing all the terps
1 Like
Makes sense.
Ok, noooob question, plz be kind:
To avoid losing terps during decarb, can you seal in canning jar, heat for correct time duration, remove, cool?
I know heating sealed anything = boom. However I’ve been told by the wyze interweb this works. Just never tried it. Anyone here try this?
yep
- So I made a thing to decarb with....
- Decarb under pressure to retain terps?
- So I made a thing to decarb with.... - #66 by Midnightoil
you might want to wrap your head around how many liters of C02 a mole of THCA will produce… or just leave copious head space 
Edit:
some may not interpret this as kind, but I’m going to point out that the link to Decarb under pressure to retain terps? was given up thread as well.
not to give you shit for not following it, but to demonstrate why reading much of this site more than once can be beneficial.
2 Likes
[edit: note that MW for THCA is wrong here. Used what the all-gnowing handed me without thinking…]
maths?!?
I’ve tried to get someone else to do this in public multiple times.
guess I’ll give it a go…
lets call 1 mole of THCA 315g, and use the approximation of 1g/ml to get the volume of our concentrate when we started. Call it 315ml.
if we start in a 1liter container, and don’t deal with the fact that the density of our extract will change as we heat it, we can pretend we have a headspace of 685ml. lets evacuate that before we start, and pretend that we actually managed to empty it. [yeah, I’m cheating…]
how about we decarb at 100C?
mainly because it’s trivial to reliably achieve and maintain.
there’s the “how many liters of C02 a mole of THCA will produce”, which is 22.4liters at STP. which is 273K or some such.
then we use PV=nRT to figure out how those 22.4l of CO2 are gonna fit in that 685mls at 100C [yep, cheating. some fraction of the terpenes will be in the headspace too!]
we have:
V=0.685L
n=1mol
T=373.14k
R=0.08206 atm L/mol.K
(lets ask the all knowing one to rearrange)
so we can get P = nRT/V
=> 0.08206*373.14/0.685 = 44.7 atm!
which the all knowing one says is 670PSI
sounds kinda** scary…
with only 31.5grams (just over and oz) in there, the math looks 10x better (ish)
0.1 x 0.08206 x 373.14 /0.9685 = 3.2 atm => 47PSI
which is why you want copious headspace.
or something that only holds some of the pressure.
** depends on your 1liter container.
if using triclamps, here’s a reminder on pressure ratings.
Edit: @Photon_noir did the math differently (and some time ago). As posted in So I made a thing to decarb with.... - #58 by TwistedStill . results look pretty similar to me. Would love confirmation. Anyone?!?
5 Likes
Anyone else playing with decarboxylation to lower temp and speed along the process?
2 Likes
did you catch that the patent is expired?
2 Likes
I have done some digging through the site archives on the subject and am quite interested in the following process, perhaps someone here has performed the experiment with success?
It looks to be fairly straightforward to push the fats and waxes away from your cannabinoids using alkali salts and an alcohol/water blend such as is detailed in the method found in the following post, it’s as simple as skimming the undesirables off and correcting the ph:
The referenced patent goes into great detail and has been updated since then and can be found here:
It’s ingenious, but any decarbed cannabinoids might be lost with the waxes as they won’t complex with the salts.
The decarb process is also very interesting but I am more interested in the initial dewaxing step as it seems very efficient to be able to skip winterization during the extraction phase.
Thoughts?
1 Like
Before I worked with hemp and cannabis I was focused on tree resin extractions centering on boswellic acids- frankincense.
Many of the patents on boswellic acid isolation use similar techniques to complex the acids with aqueous alkali salts and then flip them back Into an organic layer after filtration using an acid.
I initially used a similar technique to extract hemp but abandoned it as I found that I was losing cannabinoids with the waxes- now that I think about it the material was pretty old and probably had partially decarbed.
@CARTO.GRAPHER When I read the thread you linked to last May I completely skimmed over and skipped the initial dewax step and was focused on the thc removal/selective decarb- I never got around to trying it out though and forgot about it for a few months until I relearned it by accident a few months back, running some undecarbed oil through an alumina column- it started steaming and hissing as it released co2.
This totally clicks now- super cool- thanks for sharing!
1 Like
Prv prv prv
2 Likes
A PRV for PV=nRT is PERVERTED! 
5 Likes
Does that stirrer have an explosion proof motor? I’ve been considering this method (stainless pot on an induction heat plate w/ overhead stirrer), but figured I’d need to find a stirrer with an explosion proof motor given the solvent fumes that evolve during decarb.Then got looking at pneumatic mixers, and am now lost in a rabbit hole. (sorry if this was asked and answered already - I’m still reading thru the thread)
the majority of solvent has (should have) been recovered at this point.
AtEx rated motor should not be a requirement.
Running under an exhaust hood is advised, more for odor control that fire safety…
2 Likes
That’s reassuring coming from you. I get the impression that you take safety very seriously. Are you still decarbing by this method? Any downsides aside from potential oxidation from running the reaction in atmosphere? Is the muffin easily controllable? It looks like, between the first and second picture, the volume expansion is pretty significant. Do you find that a container double the volume of the oil is large enough to prevent spill over? Thanks!
this particular setup is not mine. I visit the lab on a regular basis, and asked if I could share these pictures. I have seen evidence that occasionally they do over flow. Seems fairly rare.
maybe @PRSPCT can address how often they’ve seen issues.
I’ve heard that before. being labeled the most safety conscious one in the room always takes me by surprise…and usually gets raucous laughter from at least one participant.
but yeah, I do try
4 Likes
Heating mantel, reflux condenser, and a chiller. Decarb and save the terps. I usually leave the top uncovered so that my residual EtOH can escape.
1 Like
We hardly ever get an over boil, with enough agitation the vortex of product keeps the offgassing managed. If you don’t have enough product or too high of a speed you’ll get some splattering. But this has worked great for us.
We do this before SPD so that we can jump straight to terp stripping and from there we only see about 6% remaining etho. Helps us manage large batches without swapping glass as often.
2 Likes
Use an air driven stirrer
2 Likes