How to Decarb Cannabis for Edibles and Topicals


How to Decarb Cannabis for Edibles and Topicals

Peg Bascom
Decarboxylating or “decarbing” cannabis refers to the process of heating the plant material at a specific temperature for a specific amount of time to activate it. Subjecting it to heat causes a chemical reaction where a carbon atom is removed from a carbon chain, resulting in the release of carbon dioxide (CO2). Key cannabinoids convert from their naturally occurring acidic forms (THCA & CBDA) into THC & CBD during decarbing. 
For example, THCA (tetrahydrocannabinolic acid) is non-psychoactive in its raw form but becomes THC after decarboxylation, and is psychoactive. Likewise, CBDA (cannabidiolic acid) is the acid precursor to CBD.
To change THCA to THC and CBDA to CBD, the raw cannabis flower must be decarboxylated (heated) first. Decarboxylating also makes certain cannabinoids, such as CBD, more bioavailable (i.e., your body can process them more easily).


  • Rimmed cookie sheet or oven-safe baking dish with a lid
  • Parchment paper cut to cover bottom of pan
  • Digital kitchen scale I like this one


  • 14 grams Dried cannabis flower 14 grams is equivalent to approximately 1/2 ounce. This amount is entirely dependent on how much cannabis flower you have available. It can be more or less than this amount.


  • Preheat your oven to the appropriate temperature for your material. See notes below.
  • Gently break up any cannabis flower or “buds” into smaller pieces. Remove any seeds or stems as needed.  There’s no need to grind it up before decarbing.
  • Using a digital scale, weigh the cannabis to your desired weight.  This step is optional but critical if your plan to use an edible dosage calculator.
  • Layer the pieces of cannabis on a cookie sheet (or covered baking dish) lined with parchment paper.  Parchment paper is needed as cannabis is very resinous and will leave a sticky residue on your cookie sheet or baking dish that can be difficult to remove.
  • If you’re using a cookie sheet, tightly cover it with aluminum foil.  You want to keep the cannabis covered so that you preserve all the cannabinoids and terpenes present in your material.
  • Place the cookie sheet or covered dish into the center of a preheated oven and bake the desired time, most commonly 40 minutes for THC-dominant cannabis.
    DO NOT open the oven, lift the lid, or otherwise check on the material.  Let it bake uninterrupted for the desired amount of time.
  • After the cooking time, remove it from the oven and let it cool completely while still being covered.
  • After the cannabis has cooled to room temperature, it should appear darker in color – usually light brown or yellow, and not as green as fresh cannabis. ***
  • Once cooled, coarsely grind the cannabis and store it in an airtight container, preferably glass.  Avoid using plastic.
  • Your decarbed flower is now ready to use!  If you don’t want to use it right away, store it in a cool, dark place.


Remember, different cannabinoids decarb at different temperature. Pick the dominant cannabinoid you know is present in your material and select the time and temperature associated with it.
THCA to THC → bake at 240º F for 40 minutes
CBDA to CBD → bake at 240º F for 90 minutes
* These instructions will work for any type of cannabis; flower, buds, trim, leaf, or shake.
** It doesn’t matter how much you decarb at one time. If it’s one gram or one ounce, the process is exactly the same.
*** At the end of the process, you are looking for a light golden-brown color and a fragrant aroma. However, if you don’t notice a color change, don’t panic. This is OK. Do not decarb any longer; go based on time.
Keyword cannabis, decarb, flower, processing