Isolating Cannabis Terpenes, Part II: Actual Process

Later this week or next I'll get some LN2 to see what it catches past the DI trap, but I will need to buy a small dewar first as they won't sell it to you otherwise.

I'm interested in the results between vacuum and not. Of course vacuum would speed it up, but I feel like if it can be achieved in an inert atmosphere with even less (or no) volatilization, the flavor profile will most closely resemble that of the plant.

Colder the better, eh? Of course. Been meaning to get a big dewar for many projects recently, let us know how it goes!

What I observed in my ultra short experience is that vacuum assists in the flow of the vapors (even with a nitrogen stream) as well as reduced temps. In theory and in practice.

On my next run I will attach a condenser or two directly to the column holding material via 24/40 adapter, no hoses, instead of using a dewar style trap with hoses. Then I'll probably use ethylene glycol or whatever solution to pump DI-CHILLED solution through the condenser.

As far as processing an extract vs plant material, why not just use a heating/stirring mantle vs vacuum open? Seems it would be much more effective. I know from solvent-free distillation experience that some of the heavier terps won't even need a cold trap.

A Kugelrohr with LN2 bath might do the trick quite effectively, for example, but maybe it will need a condenser with more direct surface area to capture everything.

Vacuum oven*

Confirmed that Blue River processes only plant material, and does/will not process concentrates.

This makes me even more confident that their process is exactly what I suspect.

Yea it wouldnt make sense to use an extract as a starting material. Bubbleman has mentioned the term hydrodiffusion a few times when discussing Blue River terps. Hydrodiffusion includes steam distillation but also can be water as a carrier at much lower temps.

Maybe LN2, light vacuum, ultrasonic mist or aerosolized water and a series of condensors/cold traps?

weedaholic721 said:

Yea it wouldnt make sense to use an extract as a starting material.

Click to expand...

Why do you say so?

Even the gentlest purge of an extract alters the terpene profile. If you want the truest representation of the flower, pulling the terpenes directly from the flower, bypassing other processes that involve heat and strong vacuum, is a win win.

One year+ anniversary post!

I've got most of my chips on BR using a freeze dryer to vape out the volatiles and condense them. It just makes the most sense to me from a timeline and logic sense, when you consider the bubble/lyophilizing process timeline. Could just be a reg vac oven too, as I believe that crew did play around with solvent extractions back in the day.

Volatilize -> Condense, KISS.
You can collect pure terps on the lid of a herb jar at atm pressures with room temp swings, if given enough time.

Multiple traps in series seems like a pain considering you have to add em all back and will get different fractions at different traps, but certainly would work well.

I'm still partial to a static vac with inert gas. Limonene regularly converts to carvone under reg atm conditions, let alone all the other effects oxygen has on the other main terps present. Static because those light trace volatiles are more prone to slip by the condensors, so why even give them a chance? Considering even the best collected terps will lose there specialness if given enough headspace in a vial or left unlidded for any short amount of time, we know the volitidy is extreme, so again why give them the chance? Sure if time and money are heavier on your scale than quality, then the efforts to reach a good efficiency is high but efficiency should be far down on the priority list of those who are just starting and havent had much or any success isolating terps/terps that smell like a fresh flower.

I'm surprised with all the vac ovens and heated shelves in the wild, that there hasnt been any posts about people putting a couple oz or a lb of frozen herb in their chambers with a high quality cold trap inline before their pumps and slowly ramp up the temps. I'd imagine even doing so in a cls column would work, but depending on packing rates probably not very efficient? Collect your terps before you loop without much modification! Even better would be to run a method like Sam's Hot Gas recirculating extraction, if I could figure out a way to recirculate gas easy and cheap thats what I'd be doing, not sure if just a simple sealed blower would work or what.

The hydrosols from my terps runs with no water added are simply amazing aroma wise, not sure if running fresh will cause more miscible hydrosol or if the miscable terps are at a fixed rate vs the water amount.


I was able to get a hold of cannabis terpenes from the space bear terp co that uses steam and herb. Bleh, smells like a old jar with no unique aroma, basically distilling it down to not much more than the main mono's, which on their own are not very desirable aromatic wise, even kinda off putting imo.

Ive still got my hands tied when it comes to terp collection, slowly but surely making headway and progress. Ive got some terp tests back from starting material that I intend to compare with isolated samples for both to see where my efficiencies are with profile ratios and yield amounts.
I have a clone that tested at 8.32% with 90% of that being terpinolene, from a 13 month cured seeded flower, which would work out to 10ml per 100g of herb if I was able to collect it all!
Not that I thought people need more incentive but its been over a year since the original post and it has moved less or as much as the growing larger thca crystals has... consider the market value of quality herb terps is, at the moment, around $200-$400/ml.........

Did you guys check out PerfumersWorld? Most everything is like $0.10/ml. I made a test order of 500ml of ethyl butyrate,

https://www.icmag.com/ic/showpost.php?p=7933632&postcount=162

And just ordered 500ml of isoamyl acetate from them,

https://www.perfumersworld.com/product/isoamyl-acetate-9FD00245

$65 delivered.


The Good Scents Company has an extensive research base,

http://www.thegoodscentscompany.com


Happy Mother's Day!!

Pangea, thanks for sharing. I'm failing to see how your freeze pump thaw degassing technique would produce results any different from collecting condensate from an inline cold trap on the exhaust line of a vacuum oven.

1. place herb in vacuum oven at room temperature
2. pull vacuum
3. increase heat gradually
4. use n2 sparge
5. collect water/terpene mix from cold traps

I have used this technique quite a bit, usually while decarbing, and while it does trap terpenes, the resulting volume is not sufficient to flavor the resulting extract from the same material.

BlackestofOps said:

Pangea, thanks for sharing. I'm failing to see how your freeze pump thaw degassing technique would produce results any different from collecting condensate from an inline cold trap on the exhaust line of a vacuum oven.

1. place herb in vacuum oven at room temperature
2. pull vacuum
3. increase heat gradually
4. use n2 sparge
5. collect water/terpene mix from cold traps

I have used this technique quite a bit, usually while decarbing, and while it does trap terpenes, the resulting volume is not sufficient to flavor the resulting extract from the same material.

Click to expand...

This method is probably more suited than repeated freeze-thaw cycles, though effectively does the same thing as you noted. Your method can always begin in a frozen state if you so wish.

As for the last part of your post, I would stick to lower temps if you want to retain much goodness (or keep it rather unaltered in flavor). If there isn't sufficient amount of terpenes collected, I would guess that you're over-pumping/under-condensing, or the material simply doesn't have those terps. How does the extract come out prior to decarboxylation?

Maybe some of you CO2 operators could shed light on this: Given that decarboxylation releases CO2 - and a reasonable quantity of it - wouldn't some terpenes naturally want to dissolve in the CO2 as they off-gas together? It might be tougher to re-condense them because of solubility, thus requiring a bit slower of flow (or an actually gradual distillation, as opposed to a single high-temp degassing stage as you currently do).

Or maybe I'm just a stoned ape with hopeful theories.

Part of the problem is that these are close to 100% trim runs, so terpene content is lower to start. The second issue is that I'm seeing some condensation on the interior of the vacuum oven, so over-pumping, I think, is not the issue. Extracts without decarbing come out (after winterizing) between 1-4% total terpene content.

As for CO2 released during decarboxylation, it would not have very much, if any, solvating ability when in such a low pressure vapor state.

So basically, place a wet bud in your microwave and see if there's any smell left.

I think the trick is using vacuum and nitrogen using microwave safe materials that won't off-gas and a very cold condenser.

What type of inert gas are you using. Also what temperature are you setting your chamber too. I know it takes really hi heat to evaporate the terpenoids, but I get a bunch off my vac oven every time. I'd like to try this

I am interested in trying to extract more terpenes prior to ethanol extraction on prime and cured flowers using AI .9 vacuum oven. Would freeze flowers to -40F, place in vacuum oven, pull vac, nitrogen sparge to cold trap. A few questions:

How long is this process under vacuum? Would you burp the vacuum at intervals or allow a slow bleed off from n2 tank to maintain vacuum?

What glass cold trap (and condenser combo?) type is recommended for this type of extraction? Would like to use dry ice/iso slurry if possible to initially test.

Does this process add any moisture to the flower material if already very dry (and cured)? Does this process affect the ability to extract thc, cbd and other terpenoids via ethanol extraction?

Enjoyed the thread!

WFF

Just a thought - Could a small amount (.5 - 1.0 lbs) of dry ice be added inside the vacuum oven (without damaging it) to pre-cool before adding plant material? I understand that the idea is let the temp slowly rise, and it should do so as the dry ice evaporates. Would the co2 gas have any effect on the n2 gas or collecting terpenoids?

As for cold traps for collection, would a series of 3-4 of these submerged in a dry ice/iso bath collect all the goodness?

Lab glass cold trap joint 24/40

Or would a larger dewar style work better? Or would I daisy chain both types together?

Dewar Condenser Flask 300mm length ID65mm&OD80mm joint 24/40

WFF

Good luck!

Entrainment of terpene(oid) in gas stream is an issue I've experienced, especially given that Anular cold traps are not really designed to "catch the terps". (really meant to minimize pump/process contamination). In vac oven, the unheated window also presents issue, as they like to condense there first. Playing with water content and other variables. Trying it with a heat mat on the window, and a new trap design that should de-entrain my target