Decarboxylation of the cannabis plant is necessary to bring out the most of the THC by converting THC(a), which is non-psychoactive, into THC which is our favorite cannabinoid.
When the cannabis plant is freshly harvested, most of the THC found within the resins on the buds and leaves, is still in it’s non-psychoactive form called THC(A). THC(A) has little to no psychoactive effect on humans when consumed. This means, if you picked a fresh “bud” from a female cannabis plant, and ate it, you would feel very little to zero “high” or psychoactive feeling.
To get cannabis that is psychoactive when consumed, the THC(A) must first be converted into THC.
In order to convert THCA into the psychoactive form we all love, called THC – cannabis must first go through a process called decarboxylation. This process usually takes place naturally in the drying and curing stage, but may also be achieved when the material is brought to a temperature of at least 122 degrees.
After about 15 minutes of 122-145 degree temperatures, THC(A) will be converted to active THC throughout the resin containing areas of the plant.
Decarboxylation Temperatures to note:
At 102 degrees, virtually all of the terpenes found in the cannabis plant will begin to evaporate off, along with most of the smells produced by those terpenes. At this point you should begin to smell a very-strong cannabis aroma. Many terpenes are lost at temperatures as low as in the high 70’s.
At 122 degrees, THC(A) begins to lose it’s carbon molecule during evaporation. This converts the THC(A) into active THC, making the material psychoactive and ready for consumption.
At 150 degrees, CBD begins to melt and evaporate. Temperatures above 150 will result in loss of CBD’s.
CBD’s, while non-psychoactive in nature, are said to be responsible for many of the medical effects of cannabis. They have been shown to relieve convulsion, inflammation, anxiety, and nausea, as well as inhibit cancer cell growth.
Any preparation of cannabinoids being used for an above condition, should not be heated above 150 degrees during the decarboxylation process, as you will diminish the amount of CBDs in the end product.
Decarboxylation rapidly takes place at approximately 220 degrees, however; as stated above with CBDs, different cannabinoids have an evaporation point of between 150 and 392 degrees. This means, heating these constituents past their evaporation point will cause them to degrade, or to be lost completely into thin air.
THC starts to rapidly evaporate at approximately 360 degrees, and completely boils away at 392 degrees. THC vapors will start to become active at approximately 114 degrees – becoming more active with longer durations and higher temperatures.
Meaning, that baking products like “medibles” at a temperature above 350 degrees, may also destroy some of the psychoactive effects.
Therefore, it is my opinion that – the most medically effective preparations are those that have been made with either naturally cured cannabis (3 weeks time or longer), or those that have been decarboxylized at temperatures between 122 and 149 degrees Fahrenheit as to keep all of the cannabinoids and other beneficial constituents in-tact.