WHAT IS DECARBOXYLATION?
Decarboxylation is a term which is thrown around a lot in the cannabis cooking world. It is of course an imperative part of the preparation of cannabis for consumption, but in my travels I have found there is not a great deal of understanding around the process. I get it- chemistry is not easy, and who hasn't glazed over when when someone starts talking about chemical bonds, carboxyl groups and stoichiometry. However, because it is so important to cooking with cannabis, we decided to jump in with both feet. So put on your thinking caps, here comes organic chemistry.
Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain.
Decarboxylation is the process that activates compounds in cannabis such as THC. All cannabinoids contained within the trichomes of raw cannabis flowers have an extra carboxyl ring or group (COOH) attached to their chain. For example, tetrahydrocannabinol acid (THCA) is synthesized within the trichome heads of freshly harvested cannabis flowers. In most regulated markets, cannabis distributed in dispensaries contains labels detailing the product’s cannabinoid contents. THCA, in many cases, prevails as the highest cannabinoid present in items that have not been decarboxylated (e.g., cannabis flowers and concentrates).
THCA has a number of known benefits when consumed, including having anti-inflammatory and neuroprotective qualities. But THCA is not intoxicating, and must be converted into THC through decarboxylation before any psychoactive effects can be felt.
The two main catalysts for decarboxylation to occur are heat and time. Drying and curing cannabis over time will cause a partial decarboxylation to occur. This is why some cannabis flowers also test for a presence of small amounts of THC along with THCA. Smoking and vaporizing will instantaneously decarboxylate cannabinoids due to the extremely high temperatures present, making them instantly available for absorption through inhalation.
While decarboxylated cannabinoids in vapor form can be easily absorbed in our lungs, edibles require these cannabinoids present in what we consume in order for our bodies to absorb them throughout digestion. Heating cannabinoids at a lower temperature over time allows us to decarboxylate the cannabinoids while preserving the integrity of the material we use so that we may infuse it into what we consume.
At What Temperature Does Decarboxylation Occur?
The THCA in cannabis begins to decarboxylate at approximately 220 degrees Fahrenheit after around 30-45 minutes of exposure. Full decarboxylation may require more time to occur. Many people choose to decarboxylate their cannabis at slightly lower temperatures for a much longer period of time in attempts to preserve terpenes. Many mono and sesquiterpenes are volatile and will evaporate at higher temperatures, leaving potentially undesirable flavors and aromas behind. The integrity of both cannabinoids and terpenes are compromised by using temperatures that exceed 300 degrees F, which is why temperatures in the 200’s are recommended.
Heat and time can also cause other forms of cannabinoid degradation to occur. For example, CBN (cannabinol) is formed through the degradation and oxidization of THC, a process that can occur alongside decarboxylation. CBN accounts for a much more sedative and less directly psychoactive experience.
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 paper, and a baking tray. Finely grind your cannabis until the material can be spread thin over parchment and placed on your baking sheet. Allow the cannabis to bake for 30-45 minutes, or longer if desired. After that it is time to infuse your decarboxylated cannabis in your fat source of choice; butter or whatever oil you fancy!