Post-Ethanol Extracted Crude to Crystallization - Crystals Without Distillation?


I’ve been lurking on these forums for a while now and I have found a ton of great information, so thanks to everyone that contributes to this site. So now on to my question.

My goal is to produce CBD isolate. For the process I am envisioning, I plan to extract hemp biomass via ethanolic extraction, winterize, then rotovap to remove ethanol, then distill for the cannabinoid fraction. At this point, I assume the distillate will have [THC] over 0.3%. From this point, I plan on recrystallizing in pentane, then mill/crush the crystals and dry.

What I am wondering is if I can get away with skipping distillation and just rotovap the ethanol away and go straight to dissolving my oil in pentane and then proceed with the crystallization. Assuming my crude is >60% CBD and <5% THC, would I still be able to crystallize CBD? What are the downsides to this and is distillation (or even chromatography) of some sort a requirement to produce isolate?

Thanks again to everyone that contributes to this great resource and I look forward to your responses.

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I’m gonna give this a shot in about a week or two. From what I’ve heard, distillation simply ensures decarb, removes terps, and gets cbd content a little higher. But that’s a ton of time and/or money for such seemingly trivial advantages it seems. Unless I’m missing something… Which could very well be the case.

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Great! I’m curious to see how that turns out. I’m just getting started so I don’t have equipment (that I can use for this at least lol) to try it myself yet.

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I’ll let you know! Just waiting on the biomass to get started at this point.

From my experience it is tough to crystallize any material that is below 70-75% by mass purity. Especially with all of the other molecules contained in crude hemp oil. How do you plan to isolate the crystals? Do you plan the free tek you found on this website or another idea?

I am trying to loosely follow the procedure outlined in this patent:

I was planning on replacing the SFE with ethanol extraction via elements of @TheLostBiologist tek and @Future tek. I plan to recover crystals via filtration on Buchner funnel, then perform a second recrystallization.


If you do a good job of controlling your extraction variables such as solvent temp and soak times, you can easily acheive a high enough purity to be able to crystallize straight out of the crude. Ethanol -46°C usually is the magic number for lipid-free extract. You will however still pull terps, gums, and other chlora. Also, if working with room-temp solvent - remember to roto down your tincture to 15:1 or 10:1 before attempting winterization otherwise nothing will coagulate out.


My question is mainly about your actual step of isolating the crystal. I am assuming you are just going to dilute and freeze which seems like what the patent suggests and that is the same free tek found on here. You may be able to get some cbd to crash out doing that it may just take quite some time. I think that SOP has about a week wait in the freezer before you see crystal.

Good luck and let us know how it goes.

With disty, warm dissolution + supersaturation with rapid cooling afterward (colder the better, -86°C is best) - we usually see significant crystallization after only a few hours.


what is the time of maximum crystal growth or rather when do you pull the jars out of the freezer?

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The patent suggests that crystallization can be completed in 24-48 hours with the distillate under ideal conditions, or as little as 12 hours. I haven’t tested it though so who knows if it works as well as the patent suggests or with a lower purity starting material :man_shrugging:

“The exact period of time required for complete crystallization of the CBD will depend on the exact conditions. Typically, in accordance with the invention, the CBD solution is kept under the temperatures recited above for a period of at least 12 hours, preferably for a period of 12-60 hours, more preferably for a period of 24-48 hours.”

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@Deleted how are you cooling to -86?


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Nice, the reason i like to take crude to dist before i induce crystallization for isolation is because i can crash in about 15-20 minutes, also it is useful to sell the intermediate processed distillate


Interesting, from distillate to crystallized product approximately how much do you yield?

60-75% yields


what is the time of maximum crystal growth or rather when do you pull the jars out of the freezer?

Few hours - usually overnight.

So you’ve confused me on this one… I assumed winterizing meant filtering frozen. The reason I ask is because I winterized with dry ice before and filtered nothing after having done the original wash at around -15°C. You make me wonder if there was too much solvent for the waxes to precipitate out. This makes much more sense I think… Awaiting for backup before I dwell on it for too long, hard to get the wrong thoughts unstuck.


That’s exactly what he meant. If the fats aren’t supersaturated in the ethanol solution, they won’t crash out when chilled