Clearing the Air – Cannabis and Decarboxylation

Debunking the Myth of THC-CBN Conversion Intensity

In the quest of manufacturing the highest-quality cannabis products, processors have undergone a sort of trial-and-error methodology. This is due, in part, by a lack of standardized procedures throughout the industry. As many have learned, without set protocols and a solid understanding of cannabis extract processing, the industry is left open to errors and unintended results.

One of the most notable is the theory of cannabis extract decarboxylation and cannabinoid conversion rates. In recent past, numerous studies and opinion pieces have stated when decarboxylating cannabis, one should exceed 70-percent decarboxylation as this can stimulate faster THC-CBN conversion than THCA-THC conversion.

A popular reasoning behind this thought process is explained in the graph. Here, we notice after 70-percent of decarboxylation is achieved, THC levels decline at a rapid rate. In doing so, the CBN ratios simultaneously rise. Ultimately, this alters the psychoactive qualities of the extract by making it more sedative in quality.

However, throughout our own research, we’ve uncovered significantly different results. Our findings have the potential to alter exactly how cannabis extract is decarboxylated to achieve the goals of various cannabis processors.

An Experiment for Truth | The Effects of Post-70% Decarboxylation on Cannabinoids

In an effort to provide further – verifiable – data, we set out to determine what happens to cannabinoids when a solution exceeds 70-percent decarboxylation. In doing so, we wished to provide additional data to manufacturers regarding the actual quantity of THC that’s converted to CBN.

The experiment went as follows:

Primary Solution | THCA Cannabis Solution

We dissolved 25 grams of Kief in 500ml of liquid coconut oil. The solution sat for two months and before starting our experiment lab analysis found the THCA solution was free from CBN. This gave us a baseline of 0.00% CBN concentration.

Decarboxylation Process | Heating the Solution

To begin, we placed the THCA solution in a one liter beaker and used the CAT MCS78 Hotplate Stirrer, set the probe temperature to 122°C and plate temperature to 350°C. Once the solution reached the set temperature the Multi-Timer automatically engaged the device for 24-hours.

Sample Collection| Precise Timing for Experiment Integrity

We collected solution samples at the following intervals:

  • 6 Hours
  • 12 Hours
  • 18 Hours
  • 24 Hours

The timing of sample collection allowed us to achieve accurate depictions of cannabinoid conversions throughout the entire decarboxylation process. During the analysis phase, we can now fully understand THC-CBN conversion ratios and rates based upon exact decarboxylation phases.

Laboratory Analysis | Experiment Results

Each of the four samples was sent to an independent laboratory for analysis. While we were confident of our anticipated results, the actual results were far greater than we previously assumed. The following is a breakdown of our discoveries:

  • Sample #1(6 Hour Collection) | THC to CBN Conversion: 0.1 mg/ml
  • Sample #2 (12 Hour Collection)| THC to CBN Conversion: 0.2 mg/ml
  • Sample #3 (18 Hour Collection)| THC to CBN Conversion: 0.3 mg/ml
  • Sample #4 (24 Hour Collection)| THC to CBN Conversion: 0.4 mg/ml

The Results of Reason | Decarboxylation Debunked

At the conclusion of our experiment, we found the rate of cannabinoid conversion is so low it’s barely noticeable. When this data is translated to real-world application, the THC-CBN conversion isn’t high enough to alter the effects of a cannabis extract. Therefore, we’re confident when using CAT Scientific products to decarboxylate your cannabis solutions, the fear of altering the psychoactive components of your products is null and void.

Have any questions? Feel free to Contact Us today, and let’s discuss how CAT Scientific can further enhance the viability, potency and consistency of your cannabis products!


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  1. Alec on February 28, 2016 at 9:39 am

    Hi Bob,
    I would like to say first of all I found your research very interesting, but on to the point…
    I recently started doing some research on what the most effective decarboxilization temperature and times are. I’ve heard things like 240 F for 30 minutes proves most effective for the highest amounts of thc, cbd and cbn. So my question is, what have your studys and personal experiences found relating to the best temperature and time to decarboxylate?
    (I plan on decarbing shatter or wax and mixing it with coconut oil and a couple tablespoons of soy lecithin, which i’ve heard makes the mixture more available to your body)

    • Bob on February 29, 2016 at 9:26 am

      For THC, the temperature is around 122-125C. CBD has a higher boiling point, decarbing starts between 138-145C. Putting a a time on decarbing is not really efficient,given we really have no idea where we started. Better to watch the C02 bubbles and when they stop, you’re decarboxylated.

      I would dissolve the wax and shatter in coconut oil(no soy lecithin) then decarboxylate.

      • Mariam on April 17, 2016 at 1:13 am

        Hi Bob!

        I am familiar with decarbing conc cannabis oil (CCO) for THC at 122*C. Nice tiny CO2 bubbles, huge amount of them, when they stop, the oil is ready and potent.

        Now I have Critical Mass 1:1 THC/CBD. My goal is to make two baches, to have THC and CBD oils separately.

        When I decarb for CBD, shall I get new lot of tiny bubbles at 138-145*C?
        Do I get rid of THC during this process?
        How long does it take to get rid of THC at 138-145*C (this is my goal) ?
        Is CBD same much stable as THC at it’s decarb temperature?

        Do I have to make two separate decarb processes or can I decarb all the lot for THC, when ready, separate my THC-oil and carry on with the rest at 138-145*C for my CBD-oil? What happens with CBDa during approx 1 hour at 122*C?

        I am self-medicating cannabis patient and I believe I need both oils separately.

        • Steve Gold on April 18, 2016 at 10:55 am

          If you have two batches of cannabis oil, THC & CBD, decraboxlate them separately. Heat your THC extract to 125C until the C02 bubbles stop. The CBD extract, heat to 138-145C, until the C02 bubbles stop as well.

          If you want to combine both cannabis oil extracts, THC & CBD, you can decarboxalyate them together. What ever device you’re using to decarb, take the temperature of the oil up to 138-145C, wait till the bubble production ceases and you’ll have fully decarbed both cannabinoids, THC & CBD.

          A CBDA extract heated to 122C for approx one hour will still be a CBDA extract because decarboxlyation doesn’t begin to happen until the oil gets to 138-145C. If you had 1:1 THC/CBD extract and decarbed @122C for an hour you’d decarb the THCA to THC, and the CBDA would still be CBDA at the end of the process.

          • Jackson Hawk on June 28, 2016 at 8:13 pm


            You state ” A CBDA extract heated to 122C for approx one hour will still be a CBDA extract because decarboxlyation doesn’t begin to happen until the oil gets to 138-145C. If you had 1:1 THC/CBD extract and decarbed @122C for an hour you’d decarb the THCA to THC, and the CBDA would still be CBDA at the end of the process.”, however, this is not what I have found to be true. Here are my personal notes from a batch of Frank’s Gift cannabis that I decarbed, then had tested:

            “Decarbing Frank’s Gift Cannabis

            I’ve been searching for a reliable way to decarboxylate medical cannabis for a while now, and there seems to be no consensus as to exactly how to do it. Different websites and forums all have a different take on the best temperature to use, how long to heat it, how to prepare it etc. My search finally led me to a British patent for a process of liquid CO2 extraction of resin from cannabis, in which they mentioned how they decarbed their samples and, most importantly, they documented the resulting lab analysis of 4 different amount of time and 3 different temperatures, and the differing results on THCa, THC, CBDa, CBD, and CBN. To me, this is a wealth of information. Here is a link to the patent:


            The 3 temps are in Celsius and translate to Fahrenheit as follows: 105° C = 221° F, 120° C = 248° F, and 140° C = 284° F.

            My takeaway from this long, very technical paper is the following 2 sentences:

            Chemovar producing primarily CBD is 1 hour at 120° C. or 0.5 hour at 140° C.
            Chemovar producing primarily THC to minimise CBN formation, is 1 to 2 hours at 105° C. or 1 hour at 120° C.

            Translation: heat your cannabis in a 120° C (248° F) oven for an hour and you are good to go. Regardless of if your cannabis is high in THC or CBD this will work very well. So I did just that (sort of) and then had the cannabis analyzed at OG Analytical in Eugene, OR. Here is what I did, the lab analysis of cured Frank’s Gift bud, and the decarbed Frank’s Gift bud.

            In the patent, they say it is preferable to dry the herb at a lower temp, then decarb it at a higher temp, but since I had put a pizza stone in the oven to try for a more even temp, I dried it and decarbed it at the same temp.

            5/10/16 I started with 36 g total; removed 1.124 g for analytical lab testing. That left @35 g before removing stems, @ 34 g after removing .9 g of stems.

            9:00 AM I put a 16″ pizza stone (9.5 lbs./4.3 Kilograms) in the oven and preheated to 250° F. I used a Farberware oven probe (laying on the pizza stone) to get an accurate temperature. It showed that it took @ 90 minutes to get up to temp.

            I was aiming for a temp of 250° F, but since my oven fluctuates about 20° F (it went from a low of about 240° F to a high of about 260° F), I could not achieve this. After almost 3 hours of screwing around with the oven, turning the temperature dial up and down, trying to get it to a stable temp, I gave up, and settled on a setting of 245° F.

            I broke up the buds into small pieces (it was very sticky), put it on an aluminum baking sheet, and put it in the oven at 11:45AM. I left it in the oven for 20 minutes to dry completely. It was not sticky at all after drying it. I crumbled up the buds in my hand (very easy) and wound up with mostly powdered bud.

            I returned the baking sheet to the oven and waited until the oven probe said 250° F, which took about 15 minutes. I left it in the oven for another hour, removed it, let it cool down a little, and weighed it. It now weighed 28 g, so it lost about 6 g of moisture (17.6%). I took out 1.15 g for the lab. Here are the lab results:

            Before Decarbing

            THCa = 4.8%
            Δ9-THC = 0.9%
            CBDa = 9.9%
            CBD = 0.6%
            CBN = <0.1%

            After Decarbing

            THCa = <0.1%
            Δ9-THC = 4.8%
            CBDa = <0.1%
            CBD = 9.1%
            CBN = 0.2%

            I am thrilled with the results – all of the THCa got converted to THC, all the CBDa got converted to CBD, and very little of the THC got degraded to CBN. Not too shabby.

            Next time I wouldn't mess with the oven temp. I would just set it at 245° F and leave it alone.

            If you look at Table 5 in the patent, you'll see that there is quite a bit of leeway in time before the THC starts to seriously degrade into CBN, so leaving it in the oven for 1-2 hours at 250° F would not degrade very much THC (4.1% after 1 hour and 6.7% after 2 hours).

            Miscellaneous notes: Franks Gift organically grown outdoors, harvested on 10/4/15, dried in 50% humidity, 70° F temp for 5 days (stems snapped at that point), then placed in 2-quart canning jars with a 62% Boveda pack for curing. It has been in the jar for 7 months."

            So, as you can see, even though the cannabis didn't even get up to 138° C (280° F) all of the CBDa was converted into CBD.

            I hope this is helpful.


      • Dante on February 25, 2018 at 10:15 pm

        Bob Quick question after dissolving shatter into coconut oil How long and at what temp should I heat it for the highest thc for edibles ? Thanks Dante

  2. Dan on April 13, 2016 at 4:56 am

    Hi Bob,

    I found the link to this site, via SkunkPharm site on decarboxylation and the well circulated chart shown above. Thanks for the great info!

    For Alec, I started making this stuff 2 years ago;

    Some tweaking of the method is that a temperature crock pot is much easier to use. The method seems to be about the best way to get max delta-9 THC and preserve terpenes that I`ve tried. Very good for pain both topically, and sublingually, and can made very potent or mild. I control IBD with about 1-1.5 teaspoons of the stuff daily.

    best regards,

  3. Craig on May 5, 2016 at 8:38 pm

    Thank you for this article, Bob. Very interesting study. Any idea where the THC went? If it didn’t break down to CBN then where’d it go?

  4. Nick on May 31, 2016 at 10:48 am

    I noticed although CBN didn’t go up much with time, THC was about at 17% after 6 hours and that THC level decreased continuously through the experiment. Have you analyzed data at shorter time intervals? Say, every hour? THC maximization seems to be the goal for many people.

  5. Mike on June 16, 2016 at 10:53 pm

    Hey there!

    Do you know of a method to increase the CBN as much as possible? I’m trying to make a very sedative extract out of whole flower and I’d like to see if I can increase the CBN to at least 10%. Is something like that possible without waiting days?

    • Reddog on November 8, 2016 at 5:17 pm

      I have the same question — what would be the ideal temp and time to convert THCa into CBN using flower? I recently decarbed a batch at 275 degrees for 4 hours (based on table 5 of the Whittle patent for cannabis extraction), and the anecdotal results seem positive.

    • Karen on October 19, 2017 at 5:51 am

      Did you ever find an answer to THC to CBN ?

    • Afternoon Jones on March 19, 2018 at 12:45 am

      THC seems to take a long time to convert to CBN even while applying heat, therefore I believe it’s best to begin with plant material that is high in CBN to make the best medicine for sleep. While the plants are growing a high CBN content can be achieved by leaving the flowers on the stems to ripen until the trichomes turn from cloudy to amber, leaving your plant with a sedative effect.

      Best of luck!

  6. Anto on September 23, 2016 at 8:18 am

    I have the same question.
    Maybe someone has an answer?

    • Karen on October 19, 2017 at 5:58 am

      Anto. Did you ever find an answer to. The THC to CBN question ?

  7. KevinSpencer on January 10, 2017 at 6:45 pm

    Same here, was wondering how to increase cbn, so need to know best way to convert thc to cbn, time and temp, etc. i have major issues sleeping and ive read 5mg of cbn is roughly equivelant to a 10mg diazepam, and dont live in colorado where cbn pills are available. Thanks in advance!

    • Karen on October 19, 2017 at 5:52 am

      Did you ever find an answer . Need CBN for sleep !!!!!

      • Afternoon Jones on March 19, 2018 at 12:41 am

        In my experience there isn’t a great way to convert THC to CBN, the best way to make an extract for sleep is to begin with high CBN content plant material. While the plants are growing high CBN can be achieved by leaving the flowers on the buds to ripen until the trichomes turn from cloudy to amber leaving your plant with have a very sedative effect.

        Because THC takes so long to convert to CBN even with heat I believe it’s best to just begin with plant material that is high in CBN.

        Best of luck!

  8. Robert Lee on February 6, 2017 at 1:30 pm

    Hi Bob! Thanks so much for the informative article, as well as the serious replies. I don’t have anything to add to the conversation as I’m here to learn, but I’m a disabled vet with insomnia problems out the wazoo. I, too, amy truly interested in maximizing CBN conversion so I don’t have to resort to the addictive meds they’re trying to prescribe me.
    Thanks again for the great research!

  9. Steve Short on March 26, 2017 at 2:12 pm

    Bob. Great work on the THC => CBN transition! Very helpful information.

    But is it possible you have made an error in that the 138 – 145 C temperature range you quote as both the boiling point of CBDA AND its decarboxylation range is not actually the decarboxylation range of CBDA which is, in reality, significantly lower?

    FYI I have always decarboxylated solvent-purged Cannabis Oil at around 110 – 120 C for around 60 – 100 minutes and continually checked for the cessation of bubbling with a large magnifier (old eyes). Yet on a number of occasions I have been distracted after seeing cessation of bubbling and towards the end of a 100 minute period accidentally allowed the temperature to rise into the 135 – 145 C region.

    However; I have never ever observed renewal of bubbling up in that higher 130 – 140 C region. Not once! To me, this tends to suggest that the true decarboxylation temperature of CBDA is definitely not as high as its boiling point i.e. not above 138 C but is much lower at around 110 – 120 C i.e. at about or only a little more than the same temperature at which THCA decarboxylates.

    Surely; if you were correct, I would see renewed bubbling up at 135 – 145 C? yet I have never seen that even with high CBDA indica strains!

  10. Steve on March 28, 2017 at 10:51 am

    Steve, Whenever we’ve decarbed CBDA extract on the MCS78 Hotplate Stirrer, bubble production didn’t start to occur until we until the solution temperature (probe temp) reached 135-145C.

    How are you decarboxalyating your solvent purged extract?

  11. Miki on April 20, 2017 at 5:45 am

    Dear Bob,

    “500ml of liquid coconut oil at 38°F”

    38°F or 38°C ??


  12. Steve Short on May 4, 2017 at 4:27 pm

    At about 120 C.

  13. Jerry Nightingale on August 25, 2017 at 6:04 pm

    To those wanting an oil with a high CBN fraction, I am wondering whether it is feasible to simply buy some CBN isolate and fortify the oil you are already using? Search on google: buy CBN isolate.

    • Karen on October 19, 2017 at 5:53 am

      Jerry, did you have any luck finding CBN isolate ?

  14. Josh on October 6, 2017 at 8:39 pm

    Bob: could you please contact me. I am a medicinal hemp producer and am trying to change our drying and curing process. Instead of naturally drying with ambient air and time we want to use a dehydrator. I would like to give you some datasets and see what you think.

    Josh @ tolbotanicals. Com

  15. Slim on October 9, 2017 at 2:18 am

    I first started decarbing cured bud according to the chart as close as i could get to 290 F for 15 min. After discovering that vape leftovers were more potent after being in the oven 15 min than bud alone it occurred to me that my time was not long enough for bud. I now go 25 min at 290 although my oven fluctuates between 250 and 300 so have added another five min. the results are quite good in spite of my lack of scientific rigor. I recently acquired an old turkey roaster and it seems to hold temps stable better than my oven so will probably move to that. Comments and suggestions welcome.

    • Slim on October 9, 2017 at 2:22 am

      meant to say i first tried it 290 for 7 min and vape leftovers more potent after 7 min

  16. Slim on October 9, 2017 at 2:21 am

    oops that first figure should read 290 F for 7 min.

  17. Andraz on October 25, 2017 at 3:05 am

    Hi, I didn’t find any answer on converting THC into CBN. We have to lower THC at least 3x and would like to know how? Please help 😀 Thanks in advance

  18. James Tripp on November 30, 2017 at 4:39 pm

    As one who is attempting to produce CBN at a home production facility, I was wondering if you have tested any degradation from THC to CBN using not only Heat, but Heat in conjunction with UV light?

  19. Pierre Ordinaire on December 1, 2017 at 4:43 pm

    Thank you so much, Bob, for the valuable information. In my very recent experience (as of today) your explanation about the different decarboxylation points of THC and CBD is correct. Originally I was planning on doing one hour at 120 C, but I observed that after the bubbling had stopped at 120 C, it would restart (as Bob said) at a higher temperature. So I took it all the way to 140 C (still safe) and kept it there until the bubbling stopped, not a minute longer not to lose THC.

  20. Denise Kress on December 10, 2017 at 11:09 am

    Hi Bob,

    Great information here. But I have a question about decarboxylating CBDa to CBD. I purchase hemp extract from Kentucky and it is primarily full of CBDa. I combine the extract with hemp seed oil on low heat briefly, so the final product still is high in CBDa. And this works for a lot of people and pets. But I want to have another formula that is all CBD. Can you please give me instructions on how to do this the best way. Can I use a double broiler or should I buy a hot plate or induction cooktop? And I blend with hemp seed oil. I’m not sure that I should beat the Hemp Seed Oil for that long. Can I just heat the extract? Thank You so much!

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