What is Decarboxylation?
Raw cannabis mainly contains THCA which is not psychoactive. When you smoke cannabis, the THCA molecule loses its carboxylic group (COOH) in the form of water vapor and carbon dioxide and becomes THC – which is psychoactive. This process of losing the carboxyl group is called “decarboxylation” or in this article “decarbing”. THCA is one of a number of cannabinoid acids such as CBDA, CBGA etc. that undergoes this process when heat or drying is applied to cannabis.
When you smoke or vaporize, the cannabis is decarbed by the heat. If you eat/ingest cannabis and want the full psychoactive effect, you need to first decarb your cannabis before you cook with it to receive the full psychoactive effect.
How to Decarboxylate?
The goal of cannabis decarbing is to activate the cannabinoids with minimal vaporization of cannabinoids or terpenes (compounds responsible for how cannabis smells). The lower the temperature, the longer the decarb time required, but less loss of terpenes due to vaporization. Heating your cannabis in a closed container will also help reduce the loss of cannabinoids and terpenes by trapping any vapor and allowing it to be reabsorbed into the cannabis material as it slowly cools down after being decarbed.
Increasing the sedative effect:
1. If you over decarb, a more sedative effect will be achieved due the degradation of THC into CBN.
2. Lower temperatures helps prevent terpenes vaporizing, but allows the conversion rate of THC to CBN to become faster than the conversion of THCA to THC. At 70% decarb the amount of THC in the cannabis actually drops since it is converting faster into CBN than the THCA is converting into THC.
Note: Grind your flower/leaves first – a course grind will allow plant material to evenly dry without losing potency from over grinding.
Note: If using an oven to decarboxylate , placing a pizza stone under the pie plate will help maintain a more even temperature
1. Preheat your oven (see table above). Use an oven thermometer to check the temperature.
2. Sprinkle your cannabis in a pie plate and then cover it well with silver foil by crimping the foil along the edge of the plate. Another option is placing the cannabis in a turkey bag, closing it up and placing it on a baking pan.
3. Place in the oven (see table above) – less time for older drier material, more for fresher material.
4. After required time, turn the oven off, and remove cannabis. Let it cool down slowly before you unseal the bag or container to allow any cannabinoid/terpenes vapor to reabsorb into the cannabis.
1. Preheat oven (see table)
2. Sprinkle hash/keif on pie plate, cover with silver foil and crimp foil along edge of plate. Place sealed dish in oven for (see table).
3. Remove plate and let it cool down slowly without removing cover to allow any vapors to reabsorb into cannabis.
Boiling Bag method:
1. Place the cannabis flower/keif/hash into a boilable cooking pouch. Seal it.
2. Place in boiling water for 90 minutes. Make sure water does not boil dry.
3. Take bag out of water. Let it slowly cool before opening.
1. Place heat proof container of cannabis oil into a cooking oil bath (canola oil works well). Heat cooking oil to 121C/250F.
2. Stir cannabis oil to break up bubbles.
3. Remove cannabis oil from heat when bubble formation starts to slow down — or leave on heat until all bubbles stop for increased sedative effect.
Update from a customer of ours:
” I was reading your handout on the basics of decarboxylation, and wanted to let you know that I have had consistent results using an oil bath. A steady 310 degrees for 30 minutes with stirring has given a complete (or nearly complete at below 1% thca) conversion on about a pint(500g) of oil. The bubbles taper off, but the line between tapering off and a finished process (at which point the bubbles presumably stop completely) can take hours, while the conversion is 99% complete after the first half hour.”
References (verified 2/11/14):
John M. McPartland and Ethan B. Russo “Cannabis and Cannabis Extracts: Greater Than the Sum of Their Parts?” http://www.cannabis-med.org/data/pdf/2001-03-04-7.pdf
Mckinney, Laurence O. (881 Massachusetts Ave., Cambridge, MA, 02139) 1981 Method and apparatus for processing herbaceous plant materials including the plant cannabis United States 4279824 http://www.freepatentsonline.com/4279824.html
Whittle, Brian (Salisbury, GB), Hill, Colin A. (Chathaml, GB), Flockhart, Ian R. (Woodmansey, GB), Downs, David Victor (Canterbury, GB), Gibson, Peter (Salisbury, GB), Wheatley, Gary William (Salisbury, GB) 2008 Extraction of pharmaceutically active components from plant materials United States GW Pharma Limited (Salisbury, GB) 7344736 http://www.freepatentsonline.com/7344736.html http://forum.grasscity.com/incredible-edible-herb/742831-badkats-cannapharm-canna-caps-uv-reactive-glowing-hash-candy-canna-bombs-more.html/page-37#entry1344628
T. Veress, J.I. Szanto, L. Leisztner, Determination of cannabinoid acids by high-performance liquid chromatography of their neutral derivatives formed by thermal decarboxylation: I. Study of the decarboxylation process in open reactors, Journal of Chromatography A, Volume 520, 9 November 1990, Pages 339-347, (http://www.sciencedirect.com/science/article/pii/002196739085118F)