Diamond SOP write-up, am I missing anything?

A bit about me first.

  • I am an educated mycologist, who left a career in food safety analytics to work in the cannabis industry.
  • Currently, I am an extraction/analytics tech at a production laboratory
  • I am working on my own experiments, in order to grow my understanding of the many processes utilized in the industry, and have been blessed with the opportunity to use the lab equipment on the weekends, as long as I bring in my own material.
  • I do have limited prior experience in the industry, as I worked for a few seasons at a facility in Washington state doing extractions, about 5 years ago. I processed their unsaleable flower into crude oil, and did color-work on it, but thats about it. It was a significantly smaller facility than my current job.

I am currently tasked with designing an SOP for diamond manufacturing, though I’m fairly certain it’s just busy work. That being said, I want to learn, and will take any slack in the rope given.

Here’s the write up for my first diamond experiment,

please advise me on my process, hollah any suggestions/changes/holes you notice in it.
Literally, anything.


If the amu of THCa is roughly 358, (which will matter later, once I actually do this)


  1. assuming 85% extraction on flower
  2. assuming 25% THCa content of flower by weight
  3. assuming perfect crystallization (for maths-sake)
  4. assuming insignificant conversion loss (again for maths-sake)
  5. assuming I don’t care about polymorphism (again, for maths-sake, though I’ll work backwards from the crystal to figure out because I want to know % terpene trapped)

For every 4.5 g of flower, one could theoretically precipitate 1 gram of crystalline THCa??

1 mole THCa = 358g

1 g THCa = .358 mole

25% by weight flower = 1 g flower = .25 g THCa = 4 g flower

85% extraction efficiency = about 4.5 g flower = nets 1 g THCa

Call it 5 grams for a bunch of elbow room in the actual physical process of extracting and precipitating,but for this theoretical phase lets keep the numbers toight.

Extraction method = super-chilled 200proof ethanol in a media bottle at 1:10 dilution

= 5 g flower (finely ground) + 45 g ethanol (.789g/ml = 57.03ml E+OH)

Shaken, not stirred, no more than a minute,

poured over a chilled vacuum funnel,

into another media bottlesample for hplc

  • Post-Extraction - (the purge)

Place media bottle, with cracked lid, in a vacuum oven set to 45c

Put ice in the dang cold-trap

Purge vacuum oven with nitrogen / turn on vacuum pump / fine-tune vacuum with nitrogen-tank valve.

Check on it periodically till there’s 1/10 remaining, volumetrically. (record times for every process)

At this point, your solution should be 99% just your solution (little to no remaining ethanol)

[idea of using the vacuum oven is to keep your solution in the jar, as opposed to dealing with scraping it in and out of reaction flasks on a roto-vape)

Turn off vacuum pump, close nitrogen valve, kill the vacuum, check your cold trap (there shouldn’t be anything there that smells, ought to be just ethanol [99%], right?)

sample anything in there for the HPLC later, and for that matter, sample your solution for the HPLC later as well.

Add to your media bottle your desired terpenes, for a 1:1 dilution (volumetrically) (sample for HPLC)

Place bottle back in vacuum oven, and repeat nitrogen purge/vacuum process (turn on your oven)

Reduce oven temperature to 40c

Leave there over-night

In the morning, sample for HPLC

Before closing down the lab that night, HPLC sample

Next day, Repeat, until you have crystals

Do not disturb solution throughout the process.

Shoot me down, punch holes in this ship, I’m just trying to figure out as much ahead of time. (i’ll be weighing things out throughout the process so that I can, in fact, work backwards once I have the crystals, because I’m working out an SOP for this)


Questions of note

  1. when to cap/is capping really necessary, or does it just expedite things? And, if so, if I have a bunch of 40l autoclaves, would that be useful, or would it just introduce moisture?

  2. I’m using ethanol, because I have it, and a lot of it (200 proof), I’m assuming everyone has solvent preferences, what are some of yours?

Based on my reading, making diamonds with ethanol can be done. It does not seem to be as trivial as the same trick performed with a hydrocarbon extract.

You loose more terpenes, and ethanol just doesn’t have the same solvation properties.

I believe @Jay-TL probably has some tips

1 Like

How so? They’re not the same solvent, so they won’t have the same properties, that’s a given. But which properties lend themselves more effectively to the precipitation of diamonds? Is it simply the increased volatility of most hydrocarbons? or does it have to do with terpenes?
(not questioning, just looking for more detail)

On the note of terpenes - I’m actually not worried about that right now (or should I be for process, not quality, reasons?) As the SOP declares that I intend on actually re-adding in terpenes for the experiment. Ideally, and once a few trial runs have occurred, I would repeat the process with rosin, instead of E+OH extract, on a commercial scale, but that is months down the line.

1 Like

Not sure if I’m clear to post. Hydrocarbons with lower boiling points are more desirable, and mixed grasses are preferred from what I understand. Again terpene preservation as the SOP for diamonds I have read tend to never surpass 85c.

I would suggest reading the strong sauce tek thread.

I’m only a scrub among these pros. But we are messing with similar SOPs currently. It’s not uncommon for me to find Crystal’s forming when emptying our roto vap, which us what led us down a similar path.

My concern is that the Etoh wont produce the same size diamonds, but more smaller Crystalline formations.

Terpene retention is the other factor. One we arent worried about as the plan would be to rinse them and sell as an isolate of sorts.

Looking forward to hearing how your R&D goes. I’d be honored if you would share.


Sort of similar to why we don’t really care about terpene preservation either, though it mostly has to do with a “we’ll deal with that refinement once we figure out the meat and potatoes” sort of perspective.

And same! Hope it turns out well, and either way, the journey ought to be very educational.

I will be posting/editing the OP with results/photos/data once the trial runs occur, though this will be a week or three away.


good luck on etoh diamonds.

you’re going to end up with some small crystalline sludge if you get any at all. you’ll need to media scrub+filtration to be successful.

1 Like

Well certainly we’ll winterize, and remove as many lipids as possible.

yes, process concern. the terpenes are probably your primary crystallization solvent when using hydrocarbons. I would guess that their relative absence might be the reason it’s harder to crystallize from ethanol.

Given thAt you’re adding terps back for this step, you’ve probably got that covered…


Why not use pentane if you are going straight for crystallization?


I think the point of reintroducing the terpenes is to get a clean PPM in their Crystals. They said they plan on washing later so they weren’t worried about terpene lose. So I assume the plan is to crystallize in terpenes then wash with cold pentane for purity, there shouldnt be any “solvent” stuck inside the lattice that way.


I was meaning, if you are going to go straight to thca, why not use pentane to extract with.

I’m still confused about using etho for the extracted solvent.

I mean, you can recover nearly all and dissolve into pentane. Then you can start your isolation.

But I also think that using a hydrocarbon to begin with would be ideal.


To necro one of my oldest threads, in honor of my return to licensed extractions, I will answer some questions, and close things out.

  • Why Ethanol and not other solvents?

    Because I could only work with ethanol at that lab/environmental constraints. :frowning:

  • Why did I not follow through with the data and post results here?

    Because I was not allowed to, and I am a respectable person, though in retrospect, that lab and its corporate self-made difficulties (that it still struggles with today) wasn’t worth what I invested of myself into it.

  • Why the long delay?

I left that lab as my spouse had landed professorships at institutions that were on the other side of the state, and as we all know, its an exceptionally finite and competitive space in the licensed side of the cannabis industry. It’s taken me this many years to find an opening at a lab in my state for extractions again, and it feels like I’ve come home. Happy to be back doesn’t cut it :face_holding_back_tears:

Anywho, hope this closes things out, sorry I can’t post any of my actual data, all I can say is that yes, you can form crystals in ethanol, no it’s not easy.

A picture of what I’ve been up to in the interim period


Welcome back!

1 Like