Hey Everyone, im a long time lurker and admirer of the great minds here.
Ive just set up a little lab for crashing out CBD isolate and its going pretty well so far, i feel like im really starting to get the process down and im making good product.
last night i pulled a batch of isolate that had an entirely different crystal formation, typically when i crash, i get crystal crusts that cover the entire surface area immersed in the solvent, this run was different, the crystals nucleated into beautiful clumps that had radiant shards all emanating from single points, in the 30-40 trays of isolate i have crashed thus far, ive never seen anything like it. What causes this deviation from the normal crust formation??
the yield of this anomalous tray was more or less in line with all my other pulls.
all parameters are the same as well, same distillate, from the the same SPD run, same plant material, same oleoresin starting weight, same solvent weight, same heating/cooling ramp, everything.
What am i missing, i mean this isnt a problem or anything, everything is crashing out and my yields are decent, im just genuinely curious as to why this phenomenon has occurred, and how can I reproduce it!!! because those crystals are gorgeous!
Also if anyone can steer me towards some resources on CBD crystallography id greatly appreciate it.
thanks,
RockSteady
apologies in advance if i posted this in the wrong section
I think I would have to know more about your process to look for some clues about what made your crystals have a variance in their lattice. Also it would help to see your prior crystals. My guess is this batch formed slower making more pure pretty crystals
I’m gonna guess that particular tray sat around a bit longer before it went into the freezer, or wasn’t disturbed as much when it was cooling down initially.
I’ve seen that difference in structure when I played around with crystallization of a couple other molecules. Most notably, if you let a cooled solution partially crash in cold temps, allow it to return to room temp, and then back in freezer.
THCA is a great example, if you cold crash before you do the full crystallization you generally get much better structures.
I start with a cryo ETOH extract using bucket tek,
then i AC scrub the extract before recovering the ETOH via rotovap
I distill the crude via SPD and collect the primary fraction,
side note: I have not needed to winterize with this method, my cryo extractions seems to be pretty on point,my distillate is crystal clear and I can crash and get decent crystal yields comparative to distillate weight usually 55-70% (this is decent right?)
I mix 1 part oleoresin to 4 parts pentane, whilst stirring I warm the solution and achieve supersaturation.
I let the solution cool down to room temp naturally over an hour,
from there i move the tray into a fridge that sits at 4C, the solution sits in the fridge for 2 hours.
after two hours have elapsed I move the tray from the fridge to the freezer, which sits at 0c, again the solution sits there for two hours. I seed the solution with 5g isolate. Finally i move the tray into a deep freezer that sits at -20c and i let it sit there for 48 hours. Then harvest time
perhaps i let it sit in the fridge or the normal freezer a little bit longer than the other trays, ill have to check my logs, which stage of the temp ramp do you think determines the major nucleation points, does it even work like that? l
Thanks for your input,
and please tear my method apart, Im trying to improve on it in anyway possible.
When you harvest, do you filter the solution out into a Buchner and wash with more pentane? or do you just decant the remaining solution and dry the crystals?
i suspect there are micro crystals in the dust in your lab now. dust/crystals land in solution and cause 100’s of nucleation sites, instead of outside crust pattern typically seen. this usually comes only after a operation has been running for a few months.
I usually do a cryo pentane after harvest to increase potency just that tiny bit more, doing a cryo wash in my limited experience is the difference between product that is 99.68% and 99.9% if you know what i mean.
to do this i use a buchner and -86c pentane. you have a tiny ammount of loss with this but the increase in potency makes it worth it. plus, the cryo wash in my experience will change the coloration from a “paper white” to a “brilliant White” as they say, the devils in the details.
I Put my distillate into those food service trays, not sure what they are called, the ones with the lids that you see at buffets, the same as the one pictured.
first i load up the tray with a measured amount of warm distillate, i heat up the distillate via water bath to around 40-45c to make pouring easy. i then add a measured amount of pentane to the tray.
i set the tray of pentane and distillate into a water bath thats around 45C, i put a clean probe into the solution a log temps, i stir the solution intill its reaches 36-37C or so (pentane boils at 37c) usually by this point, due to vigorous stiring, most of the distillate is in solution and has acheived a super saturated state, i can then start my cool down ramp. I should note that i am extra careful to make sure i have achieved super saturation, if i still see small streaks or clumps of distillate after heating i add in a tiny ammount of pentane, ie 100ml, and continue to heat and stir intill all of the distillate is off the vessel.
in my experience if you fail to get all of the distillate into solution, it will still crash, but your crystals will end up discolored and gunked up by the distillate.
I guess where I’m confused is what you’re doing with the mother liquor? This is how I am understanding it:
So after supersaturation and cooling, you pour the solution into the tray, and the CBD crashes out. Then you have a layer of CBD crystals on the bottom of the tray and a pentane solution with soluble impurities on top.
How are you removing the crystals from the bottom of the tray? Do you pour the contents of the tray (crystals and pentane solution) over the Buchner funnel and then rinse with the cryo pentane, collecting the crystals on the filter paper?
typically i decant the mothers milk and remove the crystals from the tray separately. i roto vap the mothers milk down and recover the pentane. Still trying to figure out what to do with the mother milk, its too thc hot for me to legally sell.
Gotcha, thanks for the information! Have you had any lab tests done on the mother liquor to determine how much CBD is left behind? I wonder if multiple recrystallizations on the same liquid is possible.
It gets more and more difficult as you remove the cbd to crystallize. I have results where I can typically get only about 5-10% of cbd left in the final solution and I consider this pretty solid overall yield. It also makes my recovered then treated mother liquor a rather lucrative commodity.
That makes sense. I’m going to play with some crystallization here in a bit so this is all good info. Do you re-distill the mother liquor following pentane removal? Seems you could have very little waste that way.
The unknown factor for now is that
Conversion to CBN in mother liquer
By means of oxidation treu Iodine and touleen Will.
A change thc and cbd in the liquer
B react probably with more compounds in the mother liquer
