Decarboxylating Marijuana – The Internal Process of THC Formation

August 16, 2019

Chlorophyll collects light hitting the leaves of cannabis plants. The light is stored as energy, part of which is stored to use later, and part is used to split H20 into O2 and H, oxygen and hydrogen, respectively.

This process is how plants ‘exhale’ oxygen. Plants also absorb CO2 through the reaction in photosynthesis called carboxylation. This CO2 combines with free hydrogen to create carboxylic acids.

Carboxylic acids are made up of hydrogen, carbon, and oxygen: the most relevant of these acids to growers and cultivators is delta-9-tetrahydrocannabinolic acid. Cannabidiol and Cannabinol, two other active ingredients in the plant are also made of carboxylic acids. There are a variety of other acids which have various purposes, but these three are the most relevant for most growers.

The effect of cannabinoids

The effect of cannabinoids

Delta-9-tetrahydrocannabinol (commonly called THC) has been found to have some beneficial health effects, but is not the active ingredient sought by smokers.

It doesn’t provide a “high”. While the plant is still living and growing, a large percentage of its THC remains in THCA form, which is one of the primary reasons that plants must be dried and cured to have strong drug effects. Extra CO2 molecules strongly inhibit the potency of the plant.

The THC itself is formed inside the plant through the process of decarboxylation. As suggested above, this is the removal of the extra C02 molecule.

This is one of the primary reasons why curing is such a vital part of the process of cannabis harvest. The dehydration and heat directly affect the conversion of THCA into THC, as well as determining the presence of other cannabinoids. Proper decarboxylation helps ensure the highest final yield of THC. Make sure to download my free marijuana grow bible at this link and grow like a pro!

Curing cannabis

Curing cannabis

Moisture is the most important aspect of the cannabis curing process. To begin curing, cannabis should be dried until most of the moisture has been evaporated. The best place for this is somewhere dry, dim, and cool. Good circulation is also essential.

The plant must be dried as quickly as possible. If it remains wet for an extended period of time, a grower risks the invasion of fungus and mold, which will irreparably damage the plant. Stay vigilant in the early steps of drying the plant; one of the most common mistakes is to allow a plant to rot by letting it stay moist for too long.

After the plant has dried entirely on the surface, it will still retain moisture on the inside. The next step is to place the plant matter in a sealed container and leave it. The moisture will disperse throughout the plant and rehydrate. Some growers refer to this stage of the process as sweating because moisture can condense on the interior of the container.

During the sweating stage, it’s imperative to open the jar intermittently and re-circulate the air inside the jar. This will help stave off the previously mentioned mold and fungus. Depending on the moisture of the plant matter, it may be necessary to remove the plant entirely and repeat the drying process before continuing with ‘sweating’. These two steps should be repeated as necessary until the plant matter has dried appropriately.

Decarboxylating cannabis

Decarboxylating marijuana

The heating process automatically occurs when a plant is burned, vaporized, or smoked, but for tinctures or edibles, it’s still important to make sure decarboxylation has occurred. It’s best to do this in two separate steps, in order to ensure a high quality finished product.

First, the plant matter should be broken up as much as possible. This is a basic physics concept. Smaller particle size means that there is more exposed moisture for air circulation and heat to take advantage of in the dehydration process. The smaller the pieces, the greater the surface area, and the easier and more efficient it becomes for heating. The key here is to first ensure proper dehydration of the plant matter without burning or scorching it.

It should be warmed to about 200 degrees Fahrenheit for about 15 minutes or until totally dry. Although some sources will suggest a higher temperature, it’s valuable to keep the temperature below the boiling point.

As long as the plant still contains moisture, the water can boil and damage the cells, which will destroy the integrity and appearance of the plant. Additionally, a lower temperature lowers the risk of mistakes, because there is less worry about forgetting about it. Remember, the first step is to dehydrate the plant. Don’t burn it or let it get too hot!

After the cannabis plant matter has totally dried, there is less risk in letting the temperature rise above the boiling point. Once there is no water in the plant material, raise the ambient temperature up 25 to 40 degrees, to 225 or 240 degrees Fahrenheit. Let the plant sit at this temperature for about an hour. This process will help to accelerate the decarboxylation and conversion of THCA to THC. This step requires the most care: it’s important not to let the plant ‘cook’ for too long, and, above all, make sure that it isn’t being scorched or burned at all.

Once you’ve completed these steps, you will have decarboxylated and cured your cannabis and it is ready for whatever purpose you have planned.

Thanks for reading. Please leave comments or questions below and don’t forget to download my free grow bible.


The founder of I Love Growing Marijuana, Robert Bergman, is a marijuana growing expert that enjoys sharing his knowledge with the world. He combines years of experience, ranging from small-scale grows to massive operations, with a passion for growing. His articles include tutorials on growing... [read more]


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  1. By sara fernandez ,19 Apr 2015
    Thank you for all your knowledge, i really learn alot from you!
  2. By Boyd Grant ,26 Apr 2015
    "As long as the plant still contains moisture, the water can boil and damage the cells, which will destroy the integrity and appearance of the plant." You have already done that when the cannabis was ground up. You are extracting […]Read More
  3. By Bradley ,06 Jun 2015
    Can i get some info on marijuana plant care
  4. By samneedsasmokingfriend ,24 Jun 2015
    awesome site dude. havent smoked for over 10 years but im going to take it up again. thanks for remind what wonders a simple plant can do
  5. By nakednthewoods ,24 Jul 2015
    I am growing with LEDs and know from experience the bud hairs will turn amber, and even brown, long before the tricomes on the leaves become cloudy or amber. That, my dear, is my concern. Is the condition of the […]Read More
    1. By Sust EE Nuff ,21 Feb 2017
      Hi, i was talking to a light supplier and he was telling LED is no good for growing because the light spectrum's are wrong, is this true or false.
  6. By latewood ,28 Jul 2015
    Absolutely. Although, I would say the trichomes on the bud, is what you want to look at. I am sure the leaves will be fairly close in color, though. The only way to harvest exactly at the time, for the […]Read More
    1. By Mykel ,08 Jun 2020
      so when you were describing the decarbing process you never said what to put it in, then you were talking about water boiling. What water? Are you placing the plant in water? Is it on the stove? I was always […]Read More
    2. By Mykel ,08 Jun 2020
      that wasn’t supposed to be a reply to you. Sry
  7. By jack ,01 Aug 2015
    the info you supply is great. do you suggest heating my medicine when curing for the max THC thanks jack
  8. By latewood ,05 Aug 2015
    No. Where did you get that info? You want to cure in a cool dark space with as low humidity as possible.
  9. By Wildfire: Can Burning Marijuana Fields Get You High? – I Love Growing Marijuana ,20 Aug 2015
    […] to a study Vandrey published in the journal Drug and Alcohol. Tetrahydrocannabinol (THC) from secondhand marijuana smoke can build up in a nonsmoker’s body resulting in him or […]
  10. By Is Marijuana Safe To Use ,01 Sep 2015
    […] to popular belief, marijuana is actually a remarkably safe drug. Despite the fact that THC and other cannabinoids are the primary, active ingredients, there’s no study that suggests that its lethal. Other […]
  11. By Chemical Composition Of Marijuana ,01 Sep 2015
    […] heated in cooking, the THCA is rapidly converted to active THC in a heat-propelled reaction called decarboxylation. Unlike THC, we have very little knowledge of THCA. We do know that it is not psychoactive, but it […]
  12. By dennis ,03 Sep 2015
    robert i was wondering when to stop fertilizing my osh kosh is 42 inches high and starting to bud very hairy thanks again robert get site
  13. By latewood ,04 Sep 2015
    dennis, When to stop applying nutrients is determined by the maturity of the "Trichomes. We monitor the Trichome production using a 60-100x pocket scope, jewelers loupe, etc. We want to see the perfect blend of: Clear, Cloudy, and Amber colors […]Read More
    1. By JohnPaul ,14 Nov 2015
      I'm not quite sure what you're saying because when I get the perfect blend of: Clear, Cloudy, and Amber I harvest. If you're flushing for 2 weeks AFTER you have your Perfect Blend won't that'be going past that? If I […]Read More
  14. By Preparing Cannabis For Ingestion – Medical Marijuauna Cooking – ,21 Sep 2015
    […] the THCA in the plant needs to be converted into its active form (THC) through a process called decarboxylation. The THCA is usually decarboxylated through heating and drying the plant. This will occur instantly […]
  15. By latewood.ILGM ,16 Nov 2015
    This is a matter of personal choice. Every grower applies his or her own belief as to what they see in the microscope. When you see what you perceive as the perfect balance of clear, cloudy, amber trichomes; You flush. […]Read More
  16. By Basics To Making Marijuana Edibles ,07 Mar 2016
    […] is burned, vaporized, or smoked but for tinctures or edibles, this has to be done separately. Read Decarboxylating Marijuana – The Internal Process of THC Formation and find out how decarboxylating marijuana […]
  17. By c.sabourin ,10 Mar 2016
    Am I overeading this or could the , Curing , be skipped , if, product was Decarboxylated , only , instead ? What difference would it make ?
  18. By c.sabourin ,10 Mar 2016
    Second question- If I grew Blueberry (fem.) , which can grow to 6 ft. , would be too tall for my space ( indoor ). Is it possible to trim them up to stay under 3 ft.,and yet produce their […]Read More
  19. By Lynn Nichols ,20 Feb 2017
    How do you keep plants short. Trying a tent for the first time, can't find information on it. Had to bend.
    1. By Andy ,11 Oct 2017
      You can keep your plants short a few different ways. One way is the size of the pot. If your plant is in a 1 gallon pot, it will naturally be a much smaller plant than if it was put […]Read More
  20. By latewood_ILGM ,21 Feb 2017
    Lynn, It is always good to start with a plan for new grow environments. It sounds like you grew a plant in a tent until it got too high and you bent it over. That method works, and I usae […]Read More
  21. By Patrick Pennington ,02 Jun 2017
    Do i need to decarboxalate hash from dry ice? When making e juice or oil? Thank you
    1. By Roy ILGM ,02 Jun 2017
      Hi Patrick, yes you do. Take a spoonful of your oil, hold it over a lit candle and add the hash. Good luck! – I❤️GM
  22. By Heidi Holmberg ,21 Jun 2017
    I was wondering how much stronger this process makes the pot?
  23. By Barbara Waaka ,09 Oct 2017
    I'm confused Robert ... the cannabis I have is fully dry and so I'm confused as to how to heat it to 225 f+ without it burning .. please advise and thanx for your info ... you rock xo
    1. By latewood_ILGM ,09 Oct 2017
      Barbara Waaka, You boil it in a sealed mason jar, filled to the top with your flower. Boil for one hour. Keep sealed until jar and contents are 100% cold. Good Lcuk JUst like canning except the process takes an […]Read More
  24. By Yamil Ramos Lugo ,16 Oct 2017
    Hi Robert I'm very ignorant in this subject... by heating up you mean in the oven or pan with water? Again not knowledgeable at all! Thanks
    1. By latewood_ILGM ,17 Oct 2017
      Yamil, I am not sure what you are talking about precisely... I can tell you this. You do not want to dry Cannabis in the oven, period. Dry Cannabis correctly by hanging it in an airy cool dark room. Good […]Read More
  25. By RICK ,25 Oct 2017
    1. By latewood_ILGM ,30 Oct 2017
      No. Your weed should already be dry when decarboxylating. Never use a dehydrator for cannabis in any application. undried, uncured cannabis contains too much chlorophyll.
  26. By Paul667 ,22 Nov 2017
    After I strain the weed alcohol mixture do I have to evaporate it off before adding the vg?
  27. By Robochick ,28 Nov 2017
    Hi, I’m going to be making tincture and tea at some point. Do I still need to decarboxylate for either? Won’t the alcohol have the same effect, or the boiling water with tea? How about if I store fresh straight […]Read More
  28. By Robochick ,28 Nov 2017
    Sorry, I forgot to mention, this is for max CBD, not worried about THC, in case that makes a difference! Thank you :-)
  29. By Deb P ,07 Aug 2018
    No method of decarboxylating mentioned; got this from Leafly HTH In order to decarboxylate cannabis at home, all you need is some starting material, an oven set to 220-235 degrees F (depending on your location and oven model), some parchment […]Read More
  30. By Dave ,10 Dec 2018
    I decarb in the oven then cook it in coconut and lecithin for capsules. My slow cooker gets up to 255-260 on the sides. Is that to hot? The center stays about 225.
  31. By Deborah ,12 Mar 2019
    Are you say to put the pot in water and heat it ir to bake it?
  32. By John ,15 Dec 2019
    Just want to thank Robert for all the tutorials and information. Some day I hope to be able to grow your Purple Haze and also Northern Lights. Keep up the good work.
  33. By Curtis ,04 Jan 2020
    Thank you for sharing your Experiences. Without this plant I would not be walking or sleeping.
  34. By Karél Bennett ,29 Jan 2020
    I have COPD and use a nebulator. How do I convert either herb or kiff (from the bottom of my grinder) to make a tincture that I may use in my nebulizer?
  35. By Gayle ,24 Feb 2020
    1 page says to decarboxylate at 200 for 15m which i did for an entire batch of tincture. now i read another page that says after this step to bump up the temp and bake for up to another hour. […]Read More
  36. By Jack ,17 Feb 2021
    Is decarboxylating done in water or on a cookie sheet. You talk about drying and about not letting it get above boiling. Im confused

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