Why Did Citric Acid Degumming 5x my THC:CBD ratio?

Hash and Stuff Pre/Post-Processing
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OK, this is driving me nuts trying to figure out, so hopefully smarter minds than mine can explain.

I’ve done simple winterization of crude CBD oil in our facility for years. Mix in some ethanol, chill overnight, filter through a buchner, rotovap out the solvent, very minimal processing. The filtered CBD is used for our own CBD brands as well as sold to manufacturers.
The oil we produce is usually about 50% CBD, and 2-2.5% THC (~22:1 ratio on average). We are working on some beverages so wanted to add some additional filtering to our oil to remove some more of the taste and color. I figured the Citric Acid De-gumming tek was a good way to do it (thanks Photon_noir !) quickly and efficiently. We added solvent, heated it up, added the 95/5 azeotrope, stirred in a little citric acid, and voila, it seemed to work like a charm. We could see more of the gumminess and plant lipids and chlorophyll come out of it when we chilled and ran through a paper filter like a normal secondary winterization process. Poured through a quick MagSil stack filter, and sent off for lab testing, expecting the cannabinoid concentration to go up slightly for both cannabinoids since we had just removed more of the unwanted plant material from the oil.

That’s where it got weird…

We got our lab tests back, and our CBD potency had actually dropped slightly (from ~50% to 45%. OK, no big deal, maybe we lost a little in the filtering process), but what was strange is the THC; it jumped from 2.25% to almost 6%!. We then tried the process again, this time using cold ethanol instead of room temp (still same citric acid mix) and it got even further skewed; Now the CBD potency was at 37%, but the THC potency was up to 11%! What used to be a pretty consistent 22-to-1 ratio of our cannabinoids was now closer to 3-to-1, and all we did was that citric acid degumming and another winterization pass with ethanol.

Now, I get there could be some isomerization, but it seems strange that, despite removing some of the diluting plant “gunk” from an addtional filtering process, we saw the amount of CBD per gram of filtered oil go down somewhat, while the amount of THC per gram in our newly filtered oil went up almost 500%. Is a dash of citric acid in a bit of water added to crude CBD oil suddenly the ultimate simple way to convert a ton of CBD into THC, because that doesn’t seem logical to me, but every time I try this experiment, I end up with a way higher amount of THC relative to CBD than I expect.

Any thoughts/knowledge/wild-ass guesses as to what is going on are appreciated in advance.

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You made thc from your CBD

Essentially using the citric acid tek redit finds so fascinating

See: Delta 8 conversion with citric acid

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That’s kind of the only conclusion I can come up with, but it seems like quite a lot for just a tiny bit of citric acid. I’m adding a tiny amount, and getting almost 5 times as much THC

I should also add, the lab tests should it to all be specifically delta-9 that increases, there is a sliver of delta-8 that appears on the chromatograph, but <1% in the final mix.

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Sure.

However many labs don’t have baseline separation on D8 vs D9 (some deliberately so I would wager), and D8 vs D9 is often about how long/hard you run your reaction.

There are two energy minima, D8 is a smidge lower that D9, you’re using less catalyst and lower temps than the folks deliberately trying to get from CBD to [anything that will get me high] using citric acid

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I suppose it could be the citric acid tek that @cyclopath has mentioned.

But did you test the gunk? Is it possible that you are removing more than just gums/waxes? I have seen that often in filtration steps - that we lose cannabinoids that we were expecting to keep.

You didn’t mention if you had a solid MASS BALANCE. and you didn’t mention if you tested the gunk.

If the gunk has a lot of plant gunk, fats, waxes, gums, and CBD in it - then the remaining mixture would have a ratio that was more skewed to THC.

I agree with them both that your testing lab could be terribly bad at their job as well. Huge swings are not unusual for labs with poor control charting, calibration, reference standards, and general GLP SOPs.

Did you test the gunk?

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I didn’t test the gunk, but that’s probably not a bad idea. I did push back on the lab, but they triple-checked their results and said they were right, and also expressed that they do calibrate to detect d8 vs d9, and I have no reason to think they aren’t competent at that, they are one of the main regulatory testing labs in my state.

I’ve tried the experiment a few times, and oddly enough, it seems like the THC ratio gets even higher when its run colder, which seems counter-intuitive to me if its an isomerization issue. I’m going to try a few more runs with much different (higher and lower) levels of citric acid, and see if that moves in same direction, or something else happens.

I appreciate everyone’s input, this has been making my planned SOPs for a consistent THC:CBD ratio go completely out the window.

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Few questions
You dissolve in ethanol and add citric acid correct
Do you do any additional steps to wash out the citric ? Afterwards ?
If you do a liquid to liquid extraction after Wich solvent is used ?
The water used for washing do you know it s ph ?
Is your solution neutral and in Wich solvent when you recover solvent prior to distillation
Citric acid is a bad reagent for isomerizing meaning it makes except for thc-d9 and thc-d8 quiet a lot of unknowns iso trans whatever other thc s
That most labs can not test for
I would at the same time also think that
All these steps are prior to decarboxilation and that cbd-a is still present ? Is it ?

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This is all post-decarb, with ethanol as the solvent, and filtered through a mag-sil stack. There is really no CBDa still present when this degumming step is performed.

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Ah magsil the magic powder althou known to hold on to cannabinoids mostly in the acccitic form but none the less rinse it clean with fresh solvent

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Not sure if post decarb is the right moment heat changes molecules and wonder if this makes the degumming
Not so good
@Photon_noir what’s your advise ?
At what temp do you decarb?

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Just a bit of an update on this, I have tried various tests, and incorporated some of the questions/suggestions from you guys (thanks!), and this is what I’ve come up with:

The tiny amount of citric acid added late in the process is the only variable that really moves the needle. I’ve tried it earlier in the process, decarbing at lower temp (~160 F) and chilling for longer/lower. If I leave the citric acid out of these various tests, the ratio of processed oil is still around 20-to-1 for CBD:THC. When a small amount of citric acid is added, it immediately changes that ratio down to somewhere in the 4-8 to 1 ranges. It seems that colder for longer gets me closer to the “4” than “8”, but it is still a dramatic swing even at warmer temps. The introduction of a tiny amount of citric acid dramatically increased the concentration of THC in every variation of the testing we tried.

I did try switching from a final filtering pass through MagSil to diatomaceous earth instead. The CBD:THC ratios stayed about the same, it did generate a tiny bit of detectable d-8 too, but it seemed to have an overall better effect on neutralizing some of the bitter taste of the processed oil. We are now consistently see finished oil that started at ~52% CBD/2.2% THC coming out after this tek to be ~42% CBD/10% THC. Minor cannabinoids content stayed pretty constant (~4%).

For what its worth, for those that are trying to convert CBD to THC efficiently, citric acid seems to be a cheap effective way to do so. The only side conversion I see in the lab results was a small bit of delta-8, and then only when processing through D.E instead of MagSil. all the minors seem intact, and whatever few percentage points of total cannabinoid content lost with this additional filtering was worth the improvement in taste and oil clarity.

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