Pentane recrystallization

My last batch was all small diamonds. Was looking for more info on dissolving an recrystallizing in pentane. It came up in the only the strong thread, but lookin for a little more info. Dissolve in warm pentane then cryo crash again? Leave in freezer the whole time? What temp to let sit out at?




look in the CBD threads instead.
everyone recrystallizes their CBD.
nobody recrystallizes their THC.
(broad and obviously erroneous generalization; but sound advice nonetheless)


Trying to turn small diamonds into bigger ones. Saw @Future4200 did a pentane reX on his ig a while back was trying to find some more guidelines before I try it.


In my experience, the level of pressure and temperature dictates the type and size of crystals you achieve.


This is my sop (without getting into minute details) it really only is efficient for 100+ grams of thc-a otherwise there is a significant loss
might be a little off but it will at least give you some starting points .
steps 1-6 are to purify thca to levels needed for clean ,big , easy to make crystals skip these steps and move onto step 7 if you feel your thc-a is already pure enough 90%+/-
feel free to add any advice fam. bless up

#1 separate ht from hc
#2 break up hc in uniform sand like grain
#3 add small amount of pentane to jar around a cm or less covering the bottom i like qt jars
#4 feed hc into jar slow agitation swoosh liquid around in jar you will see it start to pull the unwanted parts of the thc-a out. keep pentane in liquid state if becomes oil like viscosity add a small amount of pentane too much and you will dissolve thc-a too little and you will not be dissolving the unwanteds anymore
#5 if top liquid pentane layer is too dark and crystals on the bottom are not close to pure white let the thca settle, slowly pour off/siphon off top layer, try to stop if you see some thc-a grains coming with it.Now If liquid layer is light in color with a water like viscosity proceed to buchner funnel filtration. if not add small amount of pentane ( a few mls) untill you see a close to white color in the thca layer dont add too much ! you will dissolve more thca than wanted
#6 filtering: pour slurry into buchner funnel after filter is ready and set. add pentane (-20 -50c seems to work best) too cold and you wont dissolve undesireables too hot you will dissolve too much thca .too much pentane will dissolve too much thca as well , too little wont dissolve enough
*if you are left with dark chunks in your pure thca seperate these out repeat steps #4+
*A strainer works well for seperating the rather pure thc-a from the chunks
#7 once you are able to obtain yout purified thca granules (90%+/-) re dissolve into new pentane hotplate in safe area with minimum heat <90f .try to use as little as possible as needed or it will take longer example (77 grams in 300 ml pentane)
#8run dissolved liquid into coffee filter back into a clean jar this is to prevent unwanted seeds from starting

#9(room temp)
slowly evaporate pentane untill desired saturation level is obtained you can check this by throwing a few test seeds in the pentane if they dissolve too fast you need to evaporate more if they dissolve slowly or remain their same size you are close. If they are growing slowly this is the ideal saturation level.
#10 add big seeds( at this time your saturation and purity levels should be ideal.)
keep in mind evaporate too fast at this time and you will get unwanted contaminants trapped in the crystal lattice you want to evaporate reaaal slowy but not just sitting there or it will pause the process ( crack a ball jar lid as little as possible)
#11 if small unwanted seeds start to appear over time isolate wanted seeds repeat step #7 and up
#12 once pentane gets to the point where your crystals are not covered or your impurities are getting too concentrated ,remove the wanted seeds then fast crash the pentane solution by keeping the lid off repeat steps #4+ once solution has evaporated the pentane leaving unwanteds+ THC-A


Thanks @Terpjesus. Great info. Post my progress back up wen I get back from vacation an my pentane comes in


Do you do this with your cold crash crystals ?

I’m attempting to do a THC-A crystallization with pentane and would like some feedback/criticism if possible from those who’ve successfully used pentane as a crystallization solvent.

My starting material is BHO which has been CRC’d and dewaxed inline. It has a sugary crystalline structure, but is opaque in appearance due to high terpene content.

My procedure is as follows:
I placed ~2-3 grams of extract in a 20mL GC vial. I then pipetted room temp HPLC pentane on top of it, swirling it around until dissolved.
I ensured the solution was supersaturated by adding small amounts of BHO into solution, until no more would dissolve at room temp. I added several drops of pentane in order to get the remaining BHO crumbs to dissolve. When left outside for 20min (45-50F) the solution solidified. I added a bit of steam distilled terpenes to the top of the solution, to ensure stratification.
I then capped the vial, placed it on a digital hotplate, and have been alternating between 95F and room temperature for the past day or so, all while capped.
I’ve already noticed tiny crystals (the size of turbinado sugar crystal) forming on the bottom of the vial.
My plan is to just keep doing this to see if they continue to grow.
I think I am on the right track, but just wanted to get some feedback from the community. I’ve tried to read as many threads as I can find on the subject, but most use butane for THC-A or if pentane is used, its to recrystallize CBD.
I will post pics of my crystals when they are bigger.
Thank you in advance.


Do you happen to have pics of your end results using this tek? Thanks

Diamond thca



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God damn!
What were your perameters for that thing?!

The exact tek you posted?


What’s the weight on it?


How long/how many washes did it take to achieve this size rock?

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This one ended up a little over 100g, took maybe 10 cycles ? I was only given crude to do R&D with so every time I would get some id isolate the thca and add it to it


Nice! Yeah once they get that big it becomes difficult to get enough thca to continue to grow them even bigger. I did mine with left over jar wash and trim runs that people had laying around


My first attempt yeilded bigger diamonds then the hot jar tek.
But not 1 single rock. How are you getting it to be 1 big rock like that


start with one big seed then re dissolve extra crashed thc-a periodically. other than the diamond you are focusing on


So put in a large seed.
Once unwanted seeds form remove. Redissolve. And then repeat steps 1-7? Or 7-10?
Im assuming 7-10. Once you redissolve and have it at the saturation level thats desired, do you just pour that into the jar with the large seed?