Having Trouble Hitting 90% D9 Distillate Consistently

As the title would suggest we’re needing some help with achieving a consistent 90% D9 on our distillate. We’ve had some batches come back 89-93% D9 & almost always break the 90% range on total cannabinoids. But right now we’re averaging 85-88% Total D9
Any suggestions on how we could improve our process to help us achieve the 90% number on a constant basis would be greatly appreciated

Our extraction & Distillation methods looks like this

  • bags loaded to 30lb max with ground material no larger than 1/4th inch buds, then froze to an average temp of -25 before being extracted(input testing anywhere from 8-15%. Don’t have a metric to determine super saturation so have only washed 200-250lbs per 1000L of ethanol)

  • -50c ethanol during extraction and employ the “wash” method in place of the “soak”,

  • 20 minute “wash” cycle followed by a 10 minute “spin out” cycle

  • Once extraction is completed we go straight into “winterization”

  • Triple bag filter skid sizing down 50 :arrow_forward: 25 :arrow_forward: 10 followed by a 2.5 micron 12" double stack lenticular depth filter impregnated with diatomaceous earth & ending with a 0.5 micron microbial filter.

  • Recovered using a rising film evaporator at 40-45c

  • Decarbed in a reactor at 140c internal temp under -29inhg vacuum for 4 hours.

  • then loaded into either our 4" pope WFE or our 4" Chinese WFE under the following parameters

  • Terp strip
    Feed Rate: 5-10L/hr
    Feed: 100
    Body: 135-140
    Condenser: 35
    Vac: 400mtorr - 1torr

  • 1st pass
    Feedrate(only giving value for pope, Chinese wiper is in RPM) : .5L/hr - 1L/hr
    Feed: 100
    Body 160-170 (depending on vac & what system used)
    Condenser: 95
    Vac: 5-90 Mtorr (depending on system, pope gets down to 70-90 mtorr, chinese wiper gets down to 5mtorr )

  • 2nd pass
    FeedRate (only giving value for pope, Chinese wiper is in RPM) : 1L/hr - 1.5L/hr
    Feed: 100
    Body: 160-170 depending on system
    Condenser: 115
    Vac: 5mtorr - 90mtorr (depending on system, pope gets down to 70-90 mtorr, chinese wiper gets down to 5mtorr )

  • 3rd pass
    FeedRate (only giving value for pope, Chinese wiper is in RPM) : 1L/hr - 1.5L/hr
    Body: 160-170
    Condenser: 130
    Vac: 5mtorr - 90 mtorr (depending on system, pope gets down to 70-90 mtorr, chinese wiper gets down to 5mtorr )

Once Distillation is completed we then jar up the distillate and draw samples to send to the lab. Currently we are using little 10ml “hockey puck” like containers for sampling, I have noticed an oxidization layer form on the top every time, I am wondering if this is effecting our testing results? & if so is it an amount that is going to stop us from achieving 90% on D9


I would advise for starters to look at your input COA and extrapolate the theoretical maximum THC % if you were to hit pure cannabinoids. If your total THC divided by your total cannabinoids isn’t 90%+ then your disty won’t be either without seperating the cannabinoids. I’ve seen many scrutinize the distillation without considering the input sourcing side.


This exactly. You can’t separate cannabinoids in distillation (at least not well), so you need to always pay attention to the THC levels within the total profile of cannabinoids present in the sample. If you know you are starting out with high THC product, but are ending up with more “minor” cannabinoids, then you may want to revisit your SOP for decarbing.


you should be able to reduce your ethanol to ~1l/lb at -40C but you need to “rinse” as well as “wash” and “dry” to achieve that.

you’re not looking for super saturation.
unless you’re trying to crystalize out of ethanol.

you’re not even looking for “saturated”.

you’re looking for “saturated to the point where it doesn’t extract worth a &^(&)*#$ anymore”. (which is temperature dependent). as your dry cycle doesn’t remove all the tincture, you need a rinse with fresh solvent to make sure what IS left behind is as low in cannabinoids as possible.


For contracting farms to grow for distillate, is there a certain input biomass requirement you recommend?

Such as flower must be over 15% d9 and no more than 1% any other total cannabinoids?

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D9 Biomass Calculation for Distillate.pdf (104.9 KB)

Here’s what you might be looking for. Other variables to consider:

  • conversion rate of D9 to CBN during decarb and/or distillation (I would assume decarb as the distillation parameters are solid)
  • each cannabinoid has the same solubility in EtOH, regardless of temperature (this is not the case; for example, the XLOGP of THCa will be lower than THC due to the carboxyl group during EtOH extraction)
  • unknown compounds that are both extracted and co-distill with cannabinoids via the parameters above (sesquiterpenoids and the like)
  • The upper limit of the TAC column is relative to the THC + THCa % column. Lower THC, lower limit of TAC

When are we as a community finally going to identify these unknown compounds with a study as simple as fraction collection during distillation and GCMS identification of the compound if known or fragmentation and MW if unknown so we can identify the impurities in distillate matricies?

Thanks to @Dukejohnson for pointing out an obvious yet overlooked problem AND solution in 3 concise sentences. Sometimes the answers really do just smack you in the face, and should provide @DeltaDoode & Co with some potent knowledge to make some (more) potent disty.