Skip to content

Ultimate decryption: 4 methods for CO2 extraction of hemp for decarboxylation

Convert cannabis compounds

The original cannabis plant contains several important compounds, and carefully controlled extraction methods can unlock other compounds, such as THC.

Many of these compounds change when heated.
For example, cannabis contains THC in acid form, known as THCa (non-psychoactive substance).

When plant material is heated, THCa is converted to THC.



Before heating, natural hemp does not contain THC or CBD. In addition, it also contains its acid form, which also includes cannabinoids, THCA and CBDA. Once these are activated by the increase in temperature, this will produce the desired effect.
This process is called decarboxylation.


Decarboxylation is the heating process used to activate cannabis. Dried marijuana does not exert its full potential for psychoactive activity. Dried cannabis contains a cannabinoid called THCA or tetrahydrocannabinolic acid. Although THCA has its own benefits, it needs to be converted into THC so that cannabis has psychoactive properties and allows patients to obtain medicinal effects.

As the plant dries and ages, the process of converting THCA to THC begins. However, the plant material must be heated to speed up this conversion rate. The decarboxylation process separates the carbon molecule from the molecular chain. This process degrades (at different temperatures) the respective effective forms of cannabinoids:

 4 methods for CO2 extraction of hemp for decarboxylation

4 methods for decarboxylation of industrial hemp

Oven bake

 4 methods for CO2 extraction of hemp for decarboxylation
4 methods for CO2 extraction of hemp for decarboxylation
  • The most common way to decarboxylate industrial hemp, especially when making edible industrial hemp, is to bake it in an oven.
  • Proceed as follows:
  • Grind the industrial hemp.
  • Line a baking sheet with parchment paper.
  • Pour the grated industrial hemp into the baking paper and spread it out evenly.
  • Preheat the oven to 145°C, put the tray in the oven for about 45 minutes, and turn it over halfway.

Microwave method

If you think the 45 minutes in the oven method is too long, you can use the microwave method. This method can greatly shorten the time for decarboxylation of industrial hemp.

Methods as below:

  • As with the oven method, the industrial hemp is ground into medium particles and placed in a microwaveable bowl or plate.
  • Set the microwave oven to high heat for about 90 seconds.
  • Take out the industrial hemp and smell it. It has a pungent smell, but it succeeds without burning it.
    If it hasn’t reached this level, turn it over and put it back in the microwave for 60 to 90 seconds.
  • Compared with the oven method, heating with a microwave oven cannot control the specific temperature.
    In addition, because each microwave oven has a different temper, industrial hemp may be overcooked in minutes.
    If you are worried that the microwave method will scorch industrial hemp, you can set a lower temperature at the beginning to extend the microwave time.
    Always pay attention to industrial hemp, if the smell comes out, you can turn off the fire and bring it out.
  • Regardless of whether you choose the oven method or the microwave method to remove carboxyl groups, the key point is that the temperature should be low, don’t worry. Using high temperature to quickly heat industrial hemp will burn cannabinoids and terpenoids, which will affect the quality and aroma of industrial hemp.
    Stick to a lower temperature and take your time, and you will eventually get a completely decarboxylated industrial hemp.

Vacuum heating method

This method is the second recommended method for decarboxylation of industrial hemp (the first recommended method is the oven method).

The steps to remove the carboxyl group of industrial hemp by vacuum method are as follows:

  • Grind industrial hemp flower buds into medium particles, put them in a vacuum bag, and vacuum seal.
  • If you have a vacuum precision cooking pot, put the bag in the pot, set the temperature to 95°C, and cook for about 1 hour.
  • If you don’t have a vacuum cooking pot, you can also use a saucepan, add water to the pot and bring it to a boil.
  • After the water in the saucepan boils, lower the temperature-measure it with a thermometer, and control the water temperature to between 95 and 100°C.
  • Boil the vacuum-sealed bag in water for about 1 hour.
  • Patience is also key when using vacuum heating. This method takes significantly longer than other methods.

Natural method

In addition, if it is left in the natural environment for a long time without any treatment, the various cannabinoid acids contained in industrial hemp will naturally decarboxylate over time.
However, this process is very long, and a certain amount of heat is a necessary condition.

No matter which method you use, decarboxylation is an important process for obtaining beneficial cannabinoids.

Some tips for decarboxylation of hemp

  • Spread the hemp evenly on the baking sheet (thin layer).
  • If your hemp contains more THC and you only want to extract CBD. Heat the oven to 135° for about 45 minutes to convert cannabidiol (CBD) to CBD. This is because the decomposition temperature of CBDA is slightly higher.
  • Hemp can be wrapped in aluminum foil. Therefore, it can be put directly into the oven.
  • When the cannabis has a golden hue, it indicates that the cannabis has been well decarboxylated.

Decarboxylation of THCA or CBDA is completely incompatible

Convert THCA to THC

If your cannabis contains more THC and only needs to extract THC, preheat the oven to 115°C and place the tray in the oven for about 45 minutes. This is because the decomposition temperature of THCA is slightly lower than that of CBDA.


If you only need to extract CBD. Heat the oven to 135° for about 45 minutes to convert cannabidiol (CBD) to CBD.
This is because the decomposition temperature of CBDA is slightly higher.

Leave a Reply

Your email address will not be published. Required fields are marked *