Before you make tincture or topicals using cannabis, it is important to understand the role and process of decarboxylation (also known as "decarbing"). Decarbing activates the acid-form of the cannabinoids (THCA and CBDA) contained within raw cannabis flower into THC or CBD, so that these molecules can interact with the endocannabinoid system present throughout our brain, body, and skin. Decarbing makes cannabinoid compounds "psychoactive" which means they will produce similar effects when eaten, or applied to the skin, as they do when smoked.
Use the information on this page to learn about what decarbing is, why it is important, and follow my simple decarbing recipe to decarboxylate your own cannabis flower in preparation for making potent tincture or topicals.
What is decarboxylation?
Decarboxylation is the name for a chemical reaction which occurs when heat is applied to raw cannabis to activate the cannabinoids. Activation refers to changing the THCA molecule slightly so that it may interact with the receptors of our endocannabinoid system present throughout our brain, body, and skin. For smokable products, decarbing happens in real-time, thanks to combustion. However, for products that are consumed orally or topically, a separate decarboxylation step must take place.
Decarboxylation gets its name from the release of a carbon dioxide molecule as a result of applying a controlled amount of heat to the raw cannabis flower or concentrated oil. There are many blogs available online dedicated to the deep molecular science of exactly what is going on during decarboxylation, getting into the weeds (a pun!) of the specific science here is not necessary to understand why it is important, or what exactly is going on. Long story short, if you don't decarboxylate your cannabis, the raw form of the molecule cannot interact with our endocannabinoid system and effects of consumption will be different or reduced significantly.
Why is decarboxylation important for tincture and topicals?
Activating the THC and CBD molecule through decarboxylation enables the receptors of the endocannabinoid system to interact with the molecules, thereby providing effects similar to smoking.
Decarboxylate before or after making tincture?
It is recommended to decarboxylate the cannabis before making tincture using alcohol. If the cannabis used to make a tincture is not decarboxylated before steeping, the tincture will contain the non-psychoactive cannabis molecules THCA and CBDA. Because decarbing requires heat applied at a specific temperature, and for a certain period of time, it is not possible to decarboxylate the cannabinoid molecules while they are dissolved into an alcohol solution.
Decarboxylation Time & Temperature
Above is a chart graphic the amount of THC converted from THCA after different times and temperatures. If too much heat is applied, or applied for too long, the THC will further convert into CBN. CBN is a cannabinoid similar to THC but with effects that are reported to be significantly more sedative than uplifting. It is recommended to not over decarboxylate as the effects of CBN can easily outweigh the THC that remains.
We used the data on this chart to recommend a time of 250 degrees for 25 minutes in the oven, plus 5 minutes to rest covered, for our decarboxylation recipe (see below for step by step instructions).
The decarbing process really is that simple, but like all simple things, there are nuances and tips that we can share to improve the process outcome and yield.
Tips for Decarbing Cannabis
- Use an oven thermometer to ensure that your oven's temperature is actually 250 degrees F. Don't trust the knob or the control panel read out here, as over heating the cannabis material can result in a degradation of the THC molecule being converted. Sourcing a simple oven thermometer to confirm the internal temperature of the oven is 250 degrees is worth the investment.
- Make the cannabis as uniform as possible so that heat is applied evenly throughout the batch. Break up large buds into small chunks no bigger than 0.5 inches (1 cm) on the largest side. If you have a mix of buds and trim leaves, consider sorting and doing the decarboxylation in 2 batches. By using uniform pieces of cannabis, heat is applied more evenly and consistently throughout the batch.
- Be prepared for strong cannabis odor while decarbing. The heat applied to activate the cannabinoid molecules will also result in a significant release of the aromatic terpenes also contained in the cannabis flower. If you live in an area where strong cannabis odor may be an issue, it is recommended that you find a place to decarb with good ventilation and away from people. Consider using a small convection toaster oven outdoors as an alternative to using the oven in your kitchen.
What does decarbed cannabis look like?
Cannabis that has been decarboxylated in an oven will be slightly brown in color, and dried out to the point where it easily crumbles between finger and thumb. If the cannabis remains green, or still squishy (does not break up when squeezed) it is unlikely enough heat was applied to fully convert all of the cannabinoids into their active form.
How to tell when the decarbing process is complete?
This is, unfortunately, a very tricky answer. When decarbing raw cannabis plant material, there is no good visual way to tell if the decarboxylation process is done. Below are some suggested methods you can use as a test to confirm if the decarbing process was a success:
- Try some. Literally eat a small piece of decarbed cannabis and wait to see if effects kick in after 30 minutes to 1 hour.
- The only true way to know for sure if plant material has been fully decarbed is to have a laboratory analysis the material and report back on the amount of THC present. This answer can be discouraging to many, as it relies on faith coupled with some trial and error to know if your recipe is one to repeat. Furthermore, scouring the internet, one may notice that there are a variety of different opinions on the right amount of time and temperature to achieve a complete decarboxylation. Couple the variety of answers with the natural differences in starting plant material and there is much room for debate on how to optimize and standardize the decarbing process at home.
Steps to decarboxylate cannabis [Recipe]
Preparation: Break or chop large flowers into uniform pieces no bigger than 1/2 inch (1cm) square for even heat distribution. Preheat oven to 250 degrees Fahrenheit (120 degrees C). Confirm oven temperature using an oven thermometer. Adjust oven knob or controls to get oven to rest at 250 degrees. Trust the thermometer, not your oven's knob or digital display.
Cover a large cookie sheet in aluminum foil. Spread cannabis evenly across cookie sheet. Allow for adequate space around each piece of cannabis for maximum air flow and even heat distribution. Do not grease sheet. Do not cover in foil.
Place cookie sheet in oven. Observe oven thermometer through oven door glass window, wait for temperature to return to 250 degrees and begin timer for 25 minutes. Do not open oven while decarbing is in process.
After 25 minutes, remove cookie sheet from oven and cover in 2 layers of heavy duty aluminum foil for 5 additional minutes.
After a 5 minute rest period, remove aluminum foil cover and allow to cool to room temperature before making tincture. Store decarbed cannabis in a glass jar with a tightly sealed lid. Decarbed cannabis is ready to use as soon as it cools down. Color should be light brown, and texture of the popcorn size pieces should be frangible (break easily when squeezed between 2 fingers).
Additional Resources for Consideration
For additional scientific explanation of decarboxylation, including studies and trials with charts and data demonstrating different time and temperature combinations for decarboxylating cannabis (THC, CBD, CBG, CBN, CBV), check out these additional resources.
- Decarboxylation Study of Acidic Cannabinoids: A Novel Approach Using Ultra-High-Performance Supercritical Fluid Chromatography/Photodiode Array-Mass Spectrometry, National Library of Medicine, December 2016, Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5549281/
- Decarboxylation of Tetrahydrocannabinolic acid (THCA) to active THC, European Industrial Hemp Association (EIHA), October 2016, PDF Download: https://eiha.org/media/2014/08/16-10-25-Decarboxylation-of-THCA-to-active-THC.pdf
- Debunking the Myth of THC-CBN Conversion Intensity, Cat Scientific, Link: https://catscientific.com/decarboxylating-cannabis/