- The Weed Blog https://www.theweedblog.com

The Internal Process Of THC Formation – Decarboxylating Marijuana


Decarboxylating Marijuana THC FormationChlorophyll 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 tetrahydrocannabinol acid, cannabidiol and cannabinol

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 and grow like a pro!

The process of 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 in edibles and tinctures

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.

If you want to start growing, download my free marijuana grow bible and order some marijuana seeds. All top quality marijuana seeds are available in my marijuana seed shop. We ship seeds to the US, CA and many other countries. For any growing related question please visit the marijuana support page.



About Author

Robert Bergman is a master marijuana grower. Robert Bergman is the author of 'Marijuana Plant Care' and 'The Marijuana Grow Bible'.


  1. Bergman’s labs sucks. Wants a ton of money to get all the features and offers nothing beyond basic google information. I tried him out for a month and canceled my sub. Got a seed infected with TMV and asked the “experts” on the forums, got 4-5 different sure-thing diagnosis none which were correct. Finally figured it out myself. Seriously, just educate yourself on google, you have to weigh and vet the information yourself but bergman doesnt have a clue either so at least its free.

  2. Hey are u growing indoor or out bc that looks like one leave is burnt so lights to close, curling which idicates a deficiency, to much water and or pest. It also looks like u have a mildew (powder) or fungus of some type whats ur situation?

  3. Rolando mota on

    Hey jane I was wondering so you have year’s experience on growing marijauna can you help me figure out wats wrong with my plant. !

  4. Thank you for the corrections Matt Matt. In addition to Matt’s corrections I disagree with the statement “The plant must be dried as quickly as possible”. A good cure depends on a delicate and balanced process of moisture removal, over a considerable period of time (I prefer seven to ten days) to insure protection of the terpenes or “lipids”. Although there is much we still have to learn about this amazing plant, many concur that most of the aroma and taste is in the terpenes and there is more and more evidence to show the medicinal effects of them as well. Thanks for your efforts Mr. Bergman; I’m sure you have helped many people and yet I’m thinking you may have a way to go before calling yourself a “master marijuana grower”. I’ve been doing it for many years myself and still shy away from that title as I realize I could grow for lifetimes and still have things to learn. Peace out, Appleagate Jane

  5. Though ultimately the instructions on how to complete decarb for ingestible products is correct (cooking at 245f for about an hour would do it) some of the info on the subject is a bit iffy. For example, the curing process has nothing to do with decarboxylation and while some very small and gradual decarboxylation can and does occur as cannabis is dried, this is not the purpose. Proper decarboxylation only effects the “yield” of THC that is ingested. It makes no difference to smoked or vaporised cannabis, in fact it is an undesirable process for smoked cannabis as 1) it is unnecessary as decarboxylation will instantly occur when cannabis is vaporised and 2) many terpenes are lost after full decarb is achieved (even if done at lower temps).
    Also (and this might be a typo) you refer to THCA as THC at one point. You also described cannabinol and cannabidiol as carboxylic acids when they are not. Like THC, Cannabinol (CBN) and Cannabidiol (CBD) are decarboxilated neutral cannabinoids, otherwise referred to as “activated”. In their acidic form they are Cannabinolic acid (CBNA) and Cannabidolic Acid (CBDA), which like THCA convert to their neutral counter parts through decarboxylation. It would have also been worth noting that CBN is degraded/oxidised THC, with CBNA oxidised THCA that has not gone through decarboxylation.
    It is good to see such an important and poorly understood aspect like decarboxylation being explained, but the info provided needs amending in my opinion with these corrections

Leave A Reply