Decarboxylation studies

[Wiener_Demeanor]

Hello dear OG community,

I would like to share with you what I found from research papers on decarboxylation (decarb) of dried cannabis. I will keep this short, without going into any detail about their extraction methods and other metrics which are out of scope of my knowledge and resources. I will only represent 2 research papers i found most useful, but i will post other papers i went through on my google drive. I discarded some papers as they did not focus on decarb but more about methods of studying results, or they used material that I’m not concerned about (hemp seed pressed oil). Also, I will post papers I found interesting to understand cannabis and cannabinoids, and their extraction methods. Later on I will go through patent files and publish what I found interesting.

All my findings, summaries and conclusions are a subject to debate, if you find any mistake, some other resource that disproves something said, or have an opinion based on your experience, please comment below so that we can investigate it and find what is true, and hopefully get people who need this on right track. I am not a scientist, and this is my first time reading research papers, and looking for data.

I’ll start with this schematic to show what processes cause transformation of cannabinoids:

(from Cannabinoid Decarboxylation: A Comparative Kinetic Study)

Cannabinoid Decarboxylation: A Comparative Kinetic Study

Cannabinoid Decarboxylation A Comparative Kinetic Study.pdf (2.3 MB)

This study investigates different temperatures and timings of decarb for all main cannabinoids, both with and without present oxygen.

Summary:

Prediction model based on decarb kinetic for THC shows that best variables for total decarb are 160°C (320°F) for 6.5 minutes, and for CBD are 90°C (194°F) for 12 hours, 100°C (212°F) for 6 hours, 110°C (230°F) for 3 hours.

Eyeballing of data graphs for extracted cannabinoids show that the best (meaning not total decarb, but total decarbed yield with some precursor cannabinoids still left) temperature and timing for THC decarb is 140°C (284°F) for 20 minutes, for CBD is 120°C (248) for 50 minutes, for CBG is 120°C (120°F) for 50 minutes also.

When decarbed at 140°C (284°F) for 20 minutes, THC shows no significant degradation to CBN in any method (thin, thick fill of beaker, oxygen replaced with nitrogen).

Decarboxylation Study of Acidic Cannabinoids: A Novel Approach Using Ultra-High-Performance Supercritical Fluid Chromatography/Photodiode Array-Mass Spectrometry

Decarboxylation Study of Acidic Cannabinoids A Novel Approach Using Ultra-High-Performance Supercritical Fluid ChromatographyPhotodiode Array-Mass Spectrometry.pdf (936.2 KB)

This study is focused on decarb of cannabinoid oil extracts in vacuum oven.

Total THCa decarb is achieved at temps of 110°C, 130°C and 145°C (230°F, 266°F and 293°F) after 30, 9 and 6 minutes, with a loss of total molar concentration at temp of 110°C being 7.94%.

Since decarb was done in vacuum oven, no oxidation transformation of THC to CBN was seen.

Total CBDa decarb is achieved at 110°C and 130°C after 45 and 20 minutes, with a loss with first temp being 18.05% and with second 25.2%.

They also showed degradation of CBD due to unkown reasons, probably other biological matherial present.

Total decarb of CBG was achieved at temp of 110°C after 40 minutes, with loss of 52.67% of total molar concentration.

My toughts about it:

Altough it would be best to decarb THC material in vacuum oven, it seems thick bed of material covered with something like aluminium foil would suffice to prevent degradation into CBN. Since first study is focused mainly on total decarb, there was no data showing loss of total molar concentration in decarb of grounded herb material like they did with oil concentrate. I wish they did more studies with CBG, showing prediction model of decarb kinetics. It seems CBD and CBG take more time to decarb, but are prone to bigger degradation than THC. I will need to look into patents of extractions that are online that may have a solution of how to prevent these losses.

Here is the link to Google Drive where I stored papers i found:

https://drive.google.com/drive/folders/1O6Tu3oDknDp9jbJ82p5arcmSoRvHRJEJ?usp=sharing

Here is the link to Google drive where I will store interesting material about cannabis, cannabinoids and their extraction:

https://drive.google.com/drive/folders/1TqM2PkOQk2Li6-58Sk7k7Ltv3ZnuKrW-?usp=sharing

Peace…

[Purple-N-Hairy]

@Wiener_Demeanor

I wish they did more studies with CBG, showing prediction model of decarb kinetics

And I wish they did as comprehensive of a study with decarbing THC pulled from fresh or dried plant material using a solvent and removing the solvent through distillation.

Still, some good info to use as a reference guide for those of us who make RSO or something similar.

[Wiener_Demeanor]

Hmmm, interesting. You gave me another topic to research about. Ill see what is there.

[Wiener_Demeanor]

I haven’t seen any testing results of fresh vs dry bud extraction, but many sources state that while curing, flower is still alive and is using sugars and other to continue production of cannabinoids to some degree, and also terpenes degrade and go trought transformation producing new flavours. It would be worthwhile to investigate which polyterpenes are being made, which degrade, and to evaluate health benefits of them to define best point of extraction of them. I think i saw somewhere compared test of fresh vs dry bud terpene profile, ill try to find it.

[Wiener_Demeanor]

Here is a good info about using jar lids in pressure cooker with PET seals, and how they form harmful, mutagenic compounds while under heat:

Cannabis Decarboxylation

[Herbie]

@Wiener_Demeanor

Total CBDa decarb is achieved at 110°C and 130°C after 45 and 20 minutes, with a loss with first temp being 18.05% and with second 25.2%.

So less loss at lower heat it would seem but it takes longer for the conversion.

To me it makes little sense to try to use flower for this. In most cases the taste of chlorophyll or plant material is not going to be a positive. At least for me this is where I want to make the most of the kief etc I collect from trim.

So it is difficult to achieve and maintain such tight temps for extended periods of time. One way is a double boiler. But that only gets to 100 C or 212 F Probably could use oil instead of water and a good thermometer and set a stove to work at higher temps.

[Northern_Loki]

Some additional decarb graphs from an 2021 research paper:

The associated open-access paper, here:

molecules26144113.pdf (2.2 MB)

[Hemp]

Very cool. That is interesting.