Decarboxylating Cannabis: Turning THCA into THC

Rambo August 14, 2012 269
Decarboxylating Cannabis: Turning THCA into THC

The other day I was asked by an acquaintance why the tincture they were making had very little, if any, noticeable medicinal or psychoactive effect. They swore they followed the same process found in a book on making edibles and soaked the cannabis in high proof for weeks but the tincture just didn’t work.

The answer was simple but one that many in the cannabis industry don’t understand. One very important and necessary extra step had been overlooked. Cannabis used to make tinctures as well as other edible cannabis products requires decarboxylation. From asking around I have a feeling a lot of you just blurted out “Say What?”

So here is the deal. THCA (Tetrahydrocannabinolic Acid) is found in abundance in growing and harvested cannabis and is a biosynthetic precursor of THC (Tetrahydrocannabinol). Wow, this sounds scary like organic chemistry, doesn’t it? It is, so for both of our benefits, I’ll give you the dumbed down version.

Research suggests THCA has anti-inflammatory and neuroprotective effects but does not produce the psychoactive effect that make you feel “high”. This “high” is from the cannabinoid THC, of which little if any is found when cannabis is growing or recently harvested.

Decarboxylation is a chemical reaction that releases carbon dioxide (CO2). This means a chemical reaction takes place in which carboxylic acids loose a carbon atom from a carbon chain. This process converts THCA to THC, the much loved compound with many medicinal and psychoactive effects. When the cannabis drys, it very very slowly begins to decarboxylate and converts THCA to THC.

The good news is we don’t have to wait years for cannabis to decarboxylate. We can speed things along with a process that is a lot simpler than you might expect. Simply heating dried cannabis to the correct temperature for enough time releases that carbon dioxide and creates THC. Why have so many of you never heard of this before? Decarboxylating takes place without extra effort when cannabis is heated during the act of smoking or vaporizing. It also takes place to some degree when cannabis is cooked into butter or when hash and kief are added to a favorite recipe and then cooked in the oven.

When making tinctures, cannabis is not heated or baked, it is simply soaked in high proof alcohol. Decarboxylation never takes place and you end up with a product with a lot of THCA and very little THC. This may be a good for some symptoms but will not produce the results most expect.

Setting Up The Experiment

After explaining decarboxylation it became clear why the tincture was ineffective. Naturally they wanted to know how to decarboxylate cannabis quickly and easily so they could get on with making their tincture. I knew how to do it, but I really needed to nerd out for a bit so I could give them the best possible answer.

It really is as easy as heating the cannabis, but for how long and at what temperature? If the cannabis is heated to much, we run the risk of vaporizing and losing some of the important cannabinoids, terpenes and flavonoids which have medicinal properties. At the same time we want remove the CO2 as quickly and effectively as possible.

According to a report published by John M. McPartland and Ethan B. Russo “Cannabis and Cannabis Extracts: Greater Than the Sum of Their Parts?”, the boiling points, and hence vapor point of the major cannabinoids, terpenes, and flavonoids range from 246.2° and 435.2° Fahrenheit. I have included a substantial list taken from this report in the appendix of this article. This indicates that by staying under 246.2° Fahrenheit there should be little if any inadvertent vaporization of plant compounds that might produce medicinal benefits. I do need to qualify the above statement by saying that some terpenes actually evaporate to some degree while the plant is growing and there is not much that can be done about it.

I decided to conduct a bit of an experiment to see if my hypothesis was correct. I had some extra kief and trim that I had been keeping in storage for a rainy day. They would work perfect for the experiment and there would be no great loss if things didn’t go as planned.

Easy Steps to Decarboxylation

Consumer grade ovens are not always exact so I decided to shoot for a decarboxylation temperature of around 240° Fahrenheit. This should produce quick results without losing any medicinal potency. 30 minutes seemed like a nice round number for a first test and should give the kief and trim plenty of time to come up to temperature.

Kief has a tendency to ball up in the bag which could lead to uneven temperatures and possibly uneven decarboxylation. Before I put it in the oven, I loosened up the clumps with a fork. While most of the trim was already fairly broken up from its time in the kief tumbler, there were still some budlets in the trim that I wanted to break apart.

A few minutes in the Cuisinart works great for breaking up trim and also works well on buds if you have a bunch of joints to roll. The static from the plastic separated out some low grade kief which loosely clung to the lid of the Cuisinart. I brushed this back into the trim.

I placed a pizza stone on the middle rack of the oven and set the oven dial to bake at as close to 240° Fahrenheit as possible. Ovens lose a lot of heat when the door is opened and sometimes the temperature spikes with little explanation. The pizza stone absorbs the heat and helps maintain a constant temperature. In order to track my temperature accurately I used a thermometer with a heat resistant cord. I placed the thermometer on the pizza stone and the digital readout on the counter next to the oven where it could be monitored.

Once the temperature reached about 240° and did not appear to be increasing I placed a small Pyrex bowl of kief and another of the trim on the pizza stone. I set my timer for 30 minutes and continued to monitor the temperature. A Pyrex lasagna dish would be perfect for larger quantities. As expected, the temperature fell a few degrees from opening the door and then came back up to temperature. Throughout the half hour the temperature rose and fell several times for no apparent reason but stayed between 229° and 245° Fahrenheit.

After 30 minutes I removed both Pyrex containers with an oven mit and placed them on the counter to cool. Both the kief and the trim had noticeably fluffed up and gave off a slightly roasted scent. I took a few grams of each and packaged them for lab testing.

I returned the Pyrex dishes to the oven and set the timer for another half hour. I was pretty sure that 30 minutes had been enough to mostly decarboxylate the kief and trim, but just in case I wanted a backup test at a full hour. Either way I had to be patient and wait a few days for the test results to come back.

Results of Decarboxylation Experiment

The following charts show the results of the 30 minute and 60 minute decarboxylation experiments. Also included are the lab results from testing done prior to any artificial decarboxylation to establish a starting point. Note that because of the age of both the kief and the trim, decarboxylation had begun to take place to some degree naturally. This may not be your starting point, but should not affect the results of the experiment much.

Kief

Compound Before Decarb 30 Min Decarb 60 Min Decarb
THCA  24.5%  2.6%  .1%
THC  3.8%  25.4%  25.5%
CBDA  .6%  .3%  .3%
CBD  0%  1%  .1%
CBN  .4%  1%  1.4%
Moisture  0%  0%  0%
Total Cannabanoids  29.3%  30.3%  27.4%

Cannabis Trim

Compound Before Decarb 30 Min Decarb 60 Min Decarb
THCA  6.5%  2.9%  .2%
THC  .6%  4.8%  6.9%
CBDA  .2%  .2%  .1%
CBD  0%  0%  .1%
CBN  0%  0%  0%
Moisture  3.4%  4.5%  0%
Total Cannabanoids  7.3%  7.9%  7.3%

Testing provided by SC Labs

As you can see from the two charts, 30 minutes was not quite enough to completely decarboxylate either the kief or the trim. At 30 minutes the kief was about 90% decarboxylated but the trim was only about 60% decarboxylated. This difference is likely because the trim had a higher starting moisture content. After 60 minutes however, both keif and trim samples were close enough to 100% decarboxylation for my satisfaction.

So there you have it. 240° F for 60 minutes should be enough to decarboxylate any cannabis with a reasonably low moisture content. For material with higher moisture content, the time can be extended but the temperature should not be increased. If you are concerned about losing organic compounds, lower heat can be used but the time should be extended to compensate.

Interesting Findings

As with most experiments, the results often lead to new questions. Here are a few unexpected finding that may lead to future experiments.

The kief and trim both appear to have lost some total cannabinoids after the second 30 minutes in the oven. Some of you might suggest this is from vaporization from being at temperature for too long. This could be true, thought they were from the same plant they were not the exact same samples. Additionally lab tests do have a margin of error, so I’m not sure that is a safe assumption. This would need to be tested with more samples to have a solid verdict.

For some reason the moisture content of the trim tested higher after the first 30 minutes in the oven. I have no idea why this would be. It could just be a fluke.

Tbe CBDA did not appear to convert to CBD during the decarboxylation of the THCA. Some further research might shed some light on this.

Appendix – Cannabis Cannabinoids, Terpenes and Flavonoids

As I mentioned above, here is the list of some commonly found cannabinoids, terpenes and flavonoids that I used to pick my decarboxylation temperature. This is by no means a complete list but it’s the best I could find.

Phytocannabinoids

THC (Δ-9-tetrahydrocannabinol)
Boiling point: 157° C / 314.6° Fahrenheit
Properties: Euphoriant, Analgesic, Anti Inflammatory, Antioxidant, Antiemetic

CBD (cannabidiol)
Boiling point: 160-180°C / 320-356° Fahrenheit
Properties: Anxiolytic, Analgesic, Antipsychotic, Anti Inflammatory, Antioxidant, Antispasmodic

CBN (Cannabinol)
Boiling point: 185°C / 365° Fahrenheit
Properties: Oxidation, breakdown, product, Sedative, Antibiotic

CBC (cannabichromene)
Boiling point: 220° / 428° Fahrenheit
Properties: Anti Inflammatory, Antibiotic, Antifungal

Δ-8-THC (Δ-8-tetrahydrocannabinol)
Boiling point: 175-178°C / 347-352.4° Fahrenheit
Properties: Resembles Δ-9-THC, Less psychoactive, More stable Antiemetic

THCV (Tetrahydrocannabivarin)
Boiling point: < 220°C / <428° Fahrenheit
Properties: Analgesic, Euphoriant

Terpenoid Essential Oil Components of Cannabis

β-Myrcene
Boiling point: 166-168°C / 330.8-334.4° Fahrenheit
Properties: Analgesic. Anti Inflammatory, Antibiotic, Antimutagenic

β-Caryophyllene
Boiling point: 119°C / 246.2° Fahrenheit
Properties: Anti Inflammatory, Cytoprotective (gastric mucosa), Antimalarial

d-Limonene
Boiling point: 177°C / 350.6° Fahrenheit
Properties: Cannabinoid agonist?, Immune potentiator, Antidepressant, Antimutagenic

Linalool
Boiling point: 198°C / 388.4° Fahrenheit
Properties: Sedative, Antidepressant, Anxiolytic, Immune potentiator

Pulegone
Boiling point: 224°C / 435.2° Fahrenheit
Properties: Memory booster?, AChE inhibitor, Sedative, Antipyretic

1,8-Cineole (Eucalyptol)
Boiling point: 176°C / 348.8° Fahrenheit
Properties: AChE inhibitor, Increases cerebral, blood flow, Stimulant, Antibiotic, Antiviral, Anti Inflammatory, Antinociceptive

α-Pinene
Boiling point: 156°C / 312.8° Fahrenheit
Properties: Anti Inflammatory, Bronchodilator, Stimulant, Antibiotic, Antineoplastic, AChE inhibitor

α-Terpineol
Boiling point: 217-218°C / 422.6-424.4° Fahrenheit
Properties: Sedative, Antibiotic, AChE inhibitor, Antioxidant, Antimalarial

Terpineol-4-ol
Boiling point: 209°C / 408.2° Fahrenheit
Properties: AChE inhibitor. Antibiotic

p-Cymene
Boiling point: 177°C / 350.6° Fahrenheit
Properties: Antibiotic, Anticandidal, AChE inhibitor

Borneol
Boiling point: 210°C / 410° Fahrenheit
Properties: Antibiotic

Δ-3-Carene
Boiling point: 168*C / 334.4° Fahrenheit
Properties: Anti Inflammatory

Flavonoid and Phytosterol Components of Cannabis

Apigenin
Boiling point: 178°C / 352.4° Fahrenheit
Properties: Anxiolytic, Anti Inflammatory, Estrogenic

Quercetin
Boiling point: 250°C / 482° Fahrenheit
Properties: Antioxidant, Antimutagenic, Antiviral, Antineoplastic

Cannflavin A
Boiling point: 182°C / 359.6° Fahrenheit
Properties: COX inhibitor, LO inhibitor

β-Sitosterol
Boiling point: 134°C / 273.2° Fahrenheit
Properties: Anti Inflammatory, 5-α-reductase, inhibitor

VN:F [1.9.22_1171]
Rating: 4.7/5 (237 votes cast)

Decarboxylating Cannabis: Turning THCA into THC, 4.7 out of 5 based on 237 ratings

269 Comments »

  1. thebobsavaag January 28, 2014 at 7:48 pm -

    oh duh! I just read a little deeper and got the scoop, thanks a bunch

  2. BuddyCrocker January 30, 2014 at 1:44 pm -

    When using bubble hash, is decarbing necessary to make a tincture with Everclear?

  3. Carlo January 30, 2014 at 3:10 pm -

    how can you change CO2 concentrate which is normally dark yellow to brown and taste more or less strong like marijuana to a clear liquid with no marijuana taste and still have the same effects on the the patient using it…can you help with some information?

  4. Kidkudro February 11, 2014 at 9:25 am -

    I have found that baking my buds in the oven for 15 minutes @ 200 degrees activates the THC while preserving the CBDs.

  5. Berni February 16, 2014 at 7:33 pm -

    Would an essential oil distiller process work for extracting thc oil from plant material? For clarity, an essential oil distiller heats water covered plant material into steam. Vapor is then cooled (condensed) and collected which includes water & plant oil. Then floating essential oil is collected from top of the water. Is this possible?

    Would love to skip the butter, oil, alcohol, glycerin if possible. Thank you Rambo

  6. fuman March 2, 2014 at 6:50 am -

    So is it necessary to do decarboxylation for butter that you will bake with or will the thca be in the butter and transform during baking

  7. Dina March 3, 2014 at 7:39 am -

    I just ruined 16 gm of very nice shake trying to make a concentrated alcohol tincture for making candy. I used your decarb method, then covered the ground plant material with warm Everclear. I heated this in a hot water bath (in a Mason jar) for about four hours and took a sample, which was definitely psychoactive. I strained out the plant material at this point. I then covered the jar and put it in a water bath on the stove. I refluxed it for a couple of hours, then took the lid off and gently boiled it until it was reduced by 3/4. By this time it had turned an evil-looking brown color. I continued to reduce it, and after about 8 hours turned it off and let it sit. A scum formed on top, which I realized was esters (duh, reflux alcohol and free carboxyl groups and you WILL get esters–except, like many esters, this smells nauseating. So I haven’t thrown it out yet, but I don’t know what to do with it. I did strain the esters off and probably ruined a good strainer, but I’m afraid I’ve just learned a rather expensive lesson…any thoughts?

    • George June 2, 2014 at 10:42 pm -

      Can you please describe what you mean by “reflux”? I’m guessing it means you have a reasonably well sealed container so the alcohol vapors condense and drip back into the solution. This is how I have made my last few batches, but I have never developed any kind of scummy layer which you suspect are esters. I don’t want to run into the same issues as you, would appreciate some additional information if you are willing.

  8. jamesrhodes March 9, 2014 at 3:15 pm -

    we are a group of marijuana growers of both indoor and outdoor .and have license for the sales of medical marijuana.our cannabis has perfect THC for both average and ancient consumers . Presently there is the availability of all kinds of strains and buds .White widow,northern light ,afghan kush,hindu kush ,bubba kush,afghan incense ,master kush,strawberry kush,blueberry kush and many others etc .More so all our stuffs have their various flavours and THC and nothing has been added to it or deducted . We do express delivery to distant buyers and offer door to door delivery at clients destination for local buyers .

    Any one interested contact me 1(234) 205-1103 or email.. jamesrhrhodes2001@ gmail.com..

  9. Abdul March 27, 2014 at 3:18 am -

    Hi guys,
    I’ve been reeding up on all the posts and I’ve made a couple of batches with some great bud but to no avail.
    I used the crock pot method extracting with glycerin and decarbed at 240F for 1 hour.
    I only want to vaporize so do I need to decarb especially if I wanted my extract to keep all of its high.
    And extracting on low how many hours should I cook for.
    My purpose is to leave mixes and bongs behind not so much medicinal.

  10. Abdul March 27, 2014 at 3:41 am -

    Just me again,
    What would be the best ratio of bud to glycerin for a potent vaping experience.
    Cheer

    P.s-
    I have been googling around for months now and this page has been most helpful.
    So much to learn. Thanks everybody.

  11. MaryJaneContrary April 24, 2014 at 5:28 pm -

    Do you mind if I share your info in a cook book as long as I credit you?

  12. MaryJaneContrary April 24, 2014 at 5:29 pm -

    It’s so hard to find creditable info on decarboxylation that I’d like to pass it on.

  13. mike April 29, 2014 at 10:14 pm -

    is 240 for 60 minutes ok to decarb bho before making edies?

  14. Rooibos May 9, 2014 at 3:03 am -

    My daughter (4) is getting a THCA tincture for her brain injury. I wanted THCA because of its anti-inflammatory effects and neuroprotective effects. We are on day 10 and she has made some amazing progress. I have been putting the tincture in a bit of hot water to get rid of the alcohol but only yesterday learned that heat will covert THCA to THC which is exactly not what I want.
    My question is, can I safely use water from the kettle to get rid of the alcohol or should I just deal with the alcohol and switch to an oil CBD compound that will be safer.
    Any wisdom?

  15. Bebobwolf May 13, 2014 at 12:42 am -

    I have read your article with interest and am about to make my first batch of oil for a friend who has cancer (I haven’t personal smoked cannabis) using the following method:

    Boil for 3 hours in enclosed container.
    Then boil off alcohol etc.

    https://www.youtube.com/watch?v=2TRc99VhHRY

    I was just wondering if decarboxylation is occurring in the first phase when boiling the cannabis and alcohol for the 3 hours? or do you need a “dry heat” by using an oven?

    2nd question. How bad is the residue in the oven after the hour of decarboxylation. Will i be able to cook cakes etc afterwards without having them absorb any residue? (I have an industrial oven in my restaurant that i can use with precise temp control).

  16. himachal terepene May 22, 2014 at 12:35 am -

    It is a great process about decarboxylation.Thanks for the informatory article. It is not so difficult procedure if you follow the valid procedure. but you may lose some amount of the terepenes. these terpenes also have medicinal effects and that would be lost at higher temprature. so i would like to suggest you for the low temprature. Thanks for the great info on terpenes & flavanoids

  17. Scotsquatch May 27, 2014 at 9:35 am -

    If I am making an oil infusion (plant material in coconut and cacao oils) in a double boiler, will there be decarboxylation occur when the oil reaches the boiling point of water?

    Any recommended time frame for allowing full decarboxylation in oil?

  18. bongbrazil June 10, 2014 at 5:39 pm -

    Rambo, great job! I read an article the other day:

    http://www.popsci.com/diy/article/2013-04/mystery-nitrous-powered-pot-infused-liquor

    and i have a question for you. wouldn’t the nitrous oxide injected work for almost full decarboxylation? I’m not getting why he let the liquor simmer for an hour.
    And, mainly, this part of the process seem to be a little dangerous:
    “Place the sealed canister in a double boiler and let it simmer for an hour.”
    The whipper is made to resist high pressure and temperature, but I don’t feel 100% secure to do it. Is it a silly concern?

    Thanks

  19. Dev O June 16, 2014 at 6:13 pm -

    RAMBO!!! Thanks for the awesome De-Carb info confirming timing and temps by lab testing. That is soooo awesome. Im new with the edibles and recently learned of the de-carb process….who’d a known????? I discovered it quite by mistake, and am finally satisfied with timing aspect. I was worried as my supply is limited, so little room for error on my side. Wish me luck. Going to de-carb high grade (about 3.5g) and cook more in some coconut oil and try to encapsulate the THC rich oil.

  20. a June 21, 2014 at 1:41 am -

    Very good write-up. I definitely love this site. Keep it up!

  21. seth June 26, 2014 at 5:46 pm -

    Hi. So. Question. When making oil for medicine, what if any detrimental effects will I get by using a butane solvent as opposed to naptha or hexane? I follow the same method by stripping with butane and heat purging to remove the gas completely as I can and to carboxylate as well. I lack a vacuum for total purity to where I want but is what I’m doing even good for medical use? I really would like to know as it is very pertinent at this point. Thanks.

  22. Blake June 29, 2014 at 4:47 pm -

    Here are some things to do this, the decorating contractors keep doing
    the same thing never provide happens again. With all the
    provide contractors that are considered too. An air conditioning contractors who support over 10 years.
    Ask around-friends, relatives and friends dine
    at a fair estimate for most other roofing materials. Clothes that were founded to the finish,
    one of the establishment of construction contractors are right for you.

    • Dev O July 4, 2014 at 10:55 am -

      WTF dude?!?!?!?

  23. Mike July 3, 2014 at 6:22 am -

    Thanks Rambo. Quick question:

    In a glycerin extraction (for vape pens) which is double boiler cooked for 3 hours at around 190-200 F, do you think it is necessary to first decarb, or will just the cooking do the trick?

  24. mellowdaizy July 6, 2014 at 7:17 pm -

    from the looks of the comments, you haven’t responded in a while. understandable. but in case you happen to look this way again and feel moved enough to answer, my only question is….
    altitude. higher altitude, 9,00ft-10,000ft, how does it affect decarboxylation?

  25. Sommer July 7, 2014 at 8:02 am -

    Unlike in slate and would they begin the work and offer you a break for many.
    I see school bus and hear them. For construction companies and painting experience.
    My company has the necessary paint materials that may possibly
    bring in somebody else. Once you are asking to see school bus the condition of
    your purchase or remortgage then click here. Although you can get exactly what you think being a wood product.

  26. Dan July 10, 2014 at 4:05 pm -

    Okay, I take my dried trim and heat it at 240F for 60 minutes.

    What is the next step? Is this product ready to consume at this point after say grinding to a powder? Or is this the product I want to make a better firecracker or use in some other recipe that involves further heating?

    I’m a long time smoker and am currently looking for an easy method to ingest pot, particularly the broadleaves and whatnot from growing some on my own. Thanks for your time and input Rambo.

  27. Dan Seng July 31, 2014 at 5:29 pm -

    I didn’t read all the comments, but, I do believe drcarbing releases 1 hydrogen, not CO2. co2 is a completely different molecule. :)

    • power caspilmary August 5, 2014 at 12:16 pm -

      Carboxyl is CO2

  28. power caspilmary August 5, 2014 at 12:11 pm -

    Although this is a good, quick decarboxylation method, it does have some flaws. The evaporation point of a compound occurs before the boiling point. This is even more true for terpenes, which are also known as volatile oils for the reason that they break down incredibly easy. Terpenes are just as important as cannabinoids, and this should be taken into consideration while decarboxylating any cannabis product. I never go over 160° F with any process besides baking edibles, and even if baking brownies at 350°, the internal temperature won’t exceed 180°

  29. Colorado Legal August 7, 2014 at 8:30 pm -

    One more test to add to the repeat of the experiment to optimize accuracy of the data, is to do a 3rd set of parameters whereas you slow roast a 60 minute batch uninterrupted to clarify misreads of the 30 minute sample withdrawal creating a cooling valley requiring reheating of the material following closing of the oven door that was opened to collect the half-way sample. The 60 minute sample will then fit nicely with the 30 minute sample as serration of leaves to most accurately contrast the start sample in such representationally balanced alignment.