Thc-a Recrystallization (alex siegel method)

saw this on a story
i assume its pentane crude & water??



beautiful chemistry is whats going on!!!

looks like stuff nucleates/precipitates in the top phase and rests on the intermediate phase boundary untill the crystals weight becomes enough to break the surface tension of the bottom phase, and then it sinks below. kinda cool @AlexSiegel


Nailed it. I’d also add that when the crystal finally does fall it usually drags a small amount of impurities/mother liquor from the top layer. The density of the impurity cause it to float back into the top layer and clean the crystal over time.

Thank you for the kind words!


That’s pretty fn cool. What kind of time frame is it taking for those beautiful facets? Also love seeing new ways to make stuff. Keep experimenting it what makes this job interesting.


Can you tell us more about the solvent system used here @AlexSiegel cool stuff as usual! So exciting!


3.5g high cannabinoid crude dissolved in pentane with 30ml of de ionized water ph neutral

definitely interesting and wanting to figure it out


That is fucking bad. Ass.


It takes about 3-4 days for the first crystals to drop. Then 4-5 crystals would drop per day, max. Experiments lasted about a week total. Yields were tiny considering the amount of cannabinoids in the mixture


Anyone who does a recrystallization in a hydrocarbon can apply this technique. It works best with a recrystallization of THCa that has already been purified. Pentane/heptane recrystallization works well, sitting over water and sealed at room temp.

The trick if you want these nice monocrystals is avoiding a puck in the middle layer. I’m not 100% sure how to do that at scale. If the material pucks it can be pushed down into the water layer and fished out.


Love the details. Thank you for sharing your technique. Truly innovative.


As a hobbyist, I find this fascinating, and the reason I got into this expensive hobby gone out of control… just the neat things that the laws of nature provide for.


Can you tell us more about this?

Hey John, feel free to send me a DM or ask any questions here. I think most info was covered in the previous comments

This is more of a novelty than a recommended processing method for every batch


Alex: interesting.( a credit to you!) I am curious as to what you actually think the product
is. That is to say the state of the carboxylic acid (ionized or not)
in the crystal. If ionized, it must have a counterion…or perhaps an ion pair of THCA
is crystallizing…it would be most interesting to see an ICP-MS of one of those crystals.
It would answer a lot of questions for the curious. If it is simply non-ioned H+ form crystalizing, is the water suppling the H+ and turns slightly basic?
if you run a similar volume of THCA hexane solution in a parallel jar with out
water…do you get the same phenomena? i.e., a control without water interface.


Slow growth of mono crystals is observable without water but they’ll generally grow into the side of a dish as they’re growing and end up imperfect. Some people have really solid ways to avoid that

I hadn’t thought about the THCa being seeded by or growing with deprotonated THCa. I don’t think that’s happening because so little would be in the water when compared to the heptane


I was thinking more of an interface structure with COO-- sticking into
water,a specialized monolayer induced by water, setting up a crystallization platform in hexane side…? or in similar configuration, pair bonding with the submicromolar Ca++
leaching from glass…wild stuff! Does the water interface act as a “crystallization catalyst”?
Yes, the sidewall phenomenon, is simply another interfacial surface. …
Can you substitue a teflon flask for glass?
Thanks in advance, and a very nice piece of work.


May I ask why your solvent of choice was heptane instead of pentane?

Heptane is easier to deal with in a laboratory environment at around 70-90f.

What we would normally do is suspend the oil in an ideal amount of heptane. Some amount where very little THCa will want to hang around in it but there will still be a nice mother liquor of heptane for the pigments to trap into

On top of that heptane solution you can add pentane and then allow it to evaporate slowly


You can also add other solvents to the mixture to effect the crystal shape. I would probably seed using crystals grown in a pentane mixture with ethanol

Step 1:

Use a mixture of heptane pentane with a cosolvent that encourages THCa to grow as needles and with longer terminations

Step 2:

Seed a mixture of heptane and pentane with the seeds from step 1. Grow big clear diamond shapes that aren’t just the normal heptane blocks


I’ve been enjoying the growth of the thread! I thought I’d share a quick video of some work using this tech and big thanks to Alex Siegel for sharing all the information here for us all👍