Large scale ethanol hemp extraction - agitation or no?

Was talking to someone the other day about ethanol extraction and they made the (IMO) bold claim that “any agitation” is going to release chlorophyll, but it was possible to get 90+% of the cannabinoids extracted by doing a single wash and drain @ -20C with no or minimal chlorophyll extracted.

I agree that at colder temps you’ll minimize chlorophyll pickup relative to a room temp extraction, but my enough-to-get-me-in-trouble understanding of chemistry and physics says that without agitation you run the risk of stagnant solvent doing less than you want it to be, air bubbles and physical landscape of the biomass preventing/slowing solvent ingress or reducing drainage when your soak cycle is over.

Now, like everybody else in the hemp game I want to maximize the amount of CBD I can extract from a given amount of biomass. From a time/labor standpoint I want to do one pass with solvent and then send my biomass to the centrifuge to get the max solvent recovery possible.

My pragmatic side says that you can remediate for color after extraction, but its not so easy to remediate for CBD left in your biomass without essentially doubling your labor to re-process biomass a second time.

With that said, I also see some logistical problems that might steer a person away from agitation - if you use a compressed air source to bubble your slurry, you can certainly dilute the proof of your solvent with water if you aren’t careful. Pumps and air motors and anything else mechanical can fail and will fail with enough time, and any sort of prop is not going to be compatible with mesh bags for ease of load/unload cycles.

I am, of course, very skeptical of the claims this guy made for reasons detailed above, but I’m curious if anyone has any experience saying otherwise, or if he was just using his own theory to justify an aversion to a more complex process


I have gotten good first wash results in a sonic bath -60C 8 min 40 khz[quote=“greenbuggy, post:1, topic:2305”]


Interesting, mind sharing what kind of extraction efficiencies you were able to get with this? And was your extraction efficiency derived by pre/post extraction biomass testing or from testing crude weight and potency?

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Sad to say i live in amsterdam and everything is illegale here
I work on instinct do a singel etho wash and plant material after drying when burnt still has a cannabis smell to iT do a sonic bath singel wash No more smell i also do several batches of plant material in the same bath for i believe the ethanol is far from saturated on one batch centrifuge the batch back into the freezer and one more rinse in a new etho bath
This way i. Use 33% less ethanol same results to me

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The Delta CUP machine, Which ive heard great things about and we just got, has 3 stage cycle. Soak, Agitate, and spin dry. Without agitation ive seen you generally have to do a longer soak and leave behind more cannabanoids. The 20 minute cycle for 10-12 pounds of material with agitation is phenomenal. We also run at around -35C to -50C so maybe the colder temps allow for more agitation without absorbing as much chlorophyll. Hope that helps!

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@Siosis Have you done any tests on your pre/post extraction biomass to determine how much of the cannabinoids you are extracting vs how much is left behind?

I’ve watched the CUP video on youtube and it looks like a neat system, does it agitate by pumping solvent around or is it just spinning the bowl very slowly?

How many is several?

If the running extremely low potency material are there other issues / limiting factors than saturation levels of cannabinoids?

For example if running material that is 0.3% how many batches of biomass could be washed with the same etoh? 10x batches that would be equivalent to 3% biomass. But 10x running though crap might saturate it with junk?

Anyone have experience running extremely low potency biomass?

Obv first step would be doing actual testing but before I go that far I thought I’d ask around.

Thanks for input or direction to a previous discussion if available!

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that is gonna be a royal pain!

I’ve gone at 3% with ethanol and butane. I prefer ethanol.

the idea of targeting 0.3% with either makes my head spin. yeah, you will pull mostly unwanteds. yeah, I expect they will lower the carrying capacity for cannabinoids. I didn’t see that at 3% but I was using excess solvent.