CBD Isolation

Hopefully, the community can help clarify a few steps of CBD crystallization (typically from hemp). I’ve read through every post that I could find, but am having trouble finding the answers to the following:

  1. How can supersaturation be determined? I’ve personally experienced a number of times where seed crystals no longer dissolve in solution, but little if any isolation occurs once placed in freezer (-20F).

  2. Is there a difference between the effectiveness or yield between isolation in hexane or pentane?

  3. Are there common distillate contaminants (cannabinoids, isomers, pesticides, plant oils, etc) that cause isolation to fail or reduce yield significantly? If so, which steps can be taken to remediate?

  4. At what point can the mother liquor no longer be utilized because of high ratio of THC or other compounds?

  5. Are there compounds that boil over with hexane or pentane which will accumulate or be difficult to remove for future use in isolation?


i would also very much like to hear specifics of how people r doing this

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Yes I would love more info also

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i know this is a month old but am currently looking into this subject and want to try and bring some attention back to this thread…hoping to get some feedback :slight_smile:


bump :popcorn:

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1)Can you re-phrase the first question? Supersat will occur when molecule of interest is no longer soluable in the solution. You can run experiments to dilute with solvent and place in freezer but this is not recommended for efficient crystallization.

2)Yes there is some difference in yield. Mostly use other solvents other than hexane because of ppm levels for food grade products.

3)Mostly depends on concentration of cbd not necessarily other contaminants that I have personally observed but I also work in a rather streamlined assembly line with fairly redundant starting distillate.

4)Usually after 2 crystallizations.

5)I do not know what you mean by your last question.

Message me for more info/consults



You say that placing your crystallization material in the freezer is not recommended, because inefficient.
What is most efficient? Would it be cryo pressure vessels?

I’m doing a test in a couple of days where I’ll place my crystallization material in a beaker, on a dry ice/iso bed. Then I’ll put it in a pressure vessel. 50 psi?

Just leave me your phone number and I will call you.

You asking for everyones phone number is not very helpful for the community, and somewhat creepy. Please answer in public or use the private messaging service.


I thought this was a message my apologies. I just dont have the time to answer everyone on here via text so it is easier to call always

I would disagree and say it is helpful because we get more accomplished over the phone. These people are adults, if they dont want to message me their phone number they dont have to


Sweet tea is an example super saturation. You boil water and keep adding sugar until no more dissolves. Without having a table of solubilities of CBD at different temps for your solvent, you can’t calculate that.

For crystallization, you want a solvent that dissolves your compound really well near its boiling point, but poorly at low temperatures. This means that you want to jam as much material into the solution as possible while you can and subsequently crash it out.

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Here are pictures of my testings. @Future @QGA Any advice?

First two pictures are a 2:1 distillate to pentane left over night in the freezer.

Last picture is the same material left to room temp, then into a pressure vessel at 50 psi for a couple of hours.
There’s a clear layer of separation and it’s pretty cool looking. Guessing the bottom is isolate.

I put it back in the pressure vessel at 100 psi and going to wait till tomorrow.

Should I be putting the vessel in the freezer or chilling this?

Thank you all for your inputs.


Can you explain that a little? The third picture is solution that had been cold crashed, then pressurized? Or it had never been frozen, and crystallized from just the pressure alone?

nope! I would not drink that tea! a better example is simple syrup, which is what you described.


First 2 pics are from the material being left overnight in the freezer to start nucleation.

After that, I took it out of the freezer, let it get to room temp. Then I put it in the vessel

3rd pic is the same material after it’s been in the pressure vessel for 2 hours or so.

What was your notion in applying pressure? Hoping it would cause further precipitation or just to separate the layers like shown here?

Very interesting crystal structures by the way! How cold was your freezer?

Check out the “Strong sauce tek” topic on the forum for more info on pressure/crystallization.

Did it for a few reasons, mainly to accelerate crystallization. But it seems like the pressure is forcing all the good stuff down and seperating it better.

Plus, it’s easier to collect if it’s in one thick slab at the bottom!

Not sure about the freezer. I’d say about -20 to -30 C

Excellent questions! i’m also curious about these same topics. Did you find someone to help you out?



Did you get an answer to this question? If so, do you mind sharing?


Hey GH,

Unfortunately, I didn’t get an exact answer to the question I posted months ago.

But from the knowledge I’ve gained over the last 3 months, there is no straight answer to efficiency. People have a whooooooole bunch of different ways to isolate. It really depends on your level of knowledge/money/what works best for you.
We’ve been able to fully isolate material in less than 30m now, all with hard work and research.

I’ve seen people do an A/B water extraction, cryo freezers, pressure vessels, CPC, etc… There are so many ways to make it, and so many that are yet to be discovered. I’d say there’s no BEST way, only some that are far better than others. Again, it all depends on your knowledge and understanding what you are doing and improving on it.

Some things to look into:
-Have a look at a nucleation curve on google.
-Forcing CBD to crystallize with an exterior force.
-Slowly evaporating your solvent, while maintaining it extremely cold.

Hope it helps!