First time trying to make CBD isolate and I cannot get crystals to form. Followed the GLG “CBD Isolation by Crystallization” SOP to a T and after 72 hours at -30°c nothing. First pass CBD tested at 76%, 2:1 pentane to distillate warmed to 32°c and mixed thoroughly. Ramped down temp… room temp > refrigerated > -30° deep freeze. Any help or tips will be greatly appreciated. I just rewarmed the mixture and added more pentane to make it closer to a 3:1 as I’ve seen some users post they have better results with a more dilute mixture.
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Did you try adding a seed crystal? sprinkle in a little isolate and see if it starts to crash.
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crystals form when there is no more room in solution.
adding more solvent makes more room for solute.
which is not what you’re trying to achieve.
have you looked at: How to get cbd distillate to crystalize faster?
if you need more information on saturation and crystallization, you should check out the THCA crystallization threads. eg First try at diamonds, advice needed, please - #17 by pangea
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If you dont have any cbd isolate, try agitating it, and maybe put it under full vacuum and release it quickly. try that a few times to build some nucleation points.
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will go out and grab some isolate and try seeding. Thanks
if the seeding doesn’t help I will start over and start with something closer to 1:1 and move up from there if I continue to have issues. Thanks for the reply
You’re trying to straddle the saturation point for a really well performed crystallization, you don’t want to go to close to super-saturation and you also don’t want to be too dilute.
Was the analysis performed internally or by a 3rd party?
Were there other qualitative signs of high purity in the starting material, such as nucleation of the distillate in storage?
Practically every sample of CBD distillate or extract over 70% I’ve ever worked with would nucleate in storage after a minimum of 12 hours, and or would begin to precipitate in a reactor at -20c within the first 3 hours of the reaction reaching optimum temperature.
Your CBD molecules need to be able to “find each other” think about what conditions of your experiment might be affecting that
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Here’s some select pages from my industrial crystallization textbook from college that just happened to be on my desk that might be useful
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3rd party tested but no other signs of high purity. Distillate was made over a week ago now and its still as clear as they day it came out of the shortpath.
I personally like a 1:1 ratio of heptane or pentane to cbd distillate and throw in some seed crystal.
It usually takes 3-5 days to fully crash in a normal chest freezer that doesn’t get below -30c.
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