Like all good things, the presence of the active cannabis ingredient will tend to fall with time. THC (delta-9-tetrahydrocannabinol) is a perishable compound and factors such as light, temperature and air contribute to its slow but unstoppable decline. Most likely, you have heard that to keep cannabis, and the best is a cool, dark place. We will come closer to the reason behind it in a moment, but in general, this is a good idea when it comes to protecting the integrity of the cannabinoid content of cannabis plants.
Regardless of the level of preservation, THC levels will eventually fall. A 1999 study found that over time tetrahydrocannabinol levels decreased while CBN levels increased in properly preserved cannabis plants. The survey placed dried plant material in closed barrels contained in a ventilated dark vault. Temperatures were relatively stable, ranging between 20 and 22 degrees Celsius. To measure the degradation rate, the researchers collected samples from barrels every year over four years.
The study found that, after a year, the content of tetrahydrocannabinol decreased compared to its original quantity, starting from an average level of 16.6% of THC. After two years, it fell from its initial amount by an average of 26.8%. After three years, it decreased from its initial amount by an average of 34.5%. After four years, it dropped from its initial amount by an average of 41.4%. These percentage variations suggest that the degradation of THC is more extreme in the first year, but is reduced to an annual decrease of about 7% in the following years. The results seemed to imply that higher levels of tetrahydrocannabinol exhibited a faster rate of degradation: the more THC in the cannabis sample, the quicker it degraded in the first two years.
Of course, there is no universal degradation rate since each variety of cannabis, flower and conservation environment are different. Some bulbs can last much longer than others. This is especially true if the storage environment is cold, dark and dry (not dry).
Let’s do it… The three fastest ways to lower the THC level of your Cannabis
If you want to protect the integrity of the tetrahydrocannabinol content in your cannabis product for as long as possible, do not follow these steps. But if your harvest has a few percentage points above the set legal level (0.6% in Italy, 1% in Switzerland) and your crop is slightly higher using this method you can lower the levels of active ingredient to allow you marketing in the parameters of the law.
1-Put it in direct sunlight.
As for temperature, light instigates a biosynthetic process in a cannabis plant that results in the deterioration of its cannabinoid levels. Since 1971, the scientific community has been aware of the effects of light on THC degradation.
A study published that year concluded that the best preservation method for cannabis was under nitrogen and in the dark. A few years later, in 1976, research examining cannabinoid stability over two years found that exposure to light was the most effective “variable” for depleting all cannabinoid levels, including THC. This was particularly evident in samples of cannabis oils, a form of the plant that is more volatile than the cannabis flower.
2-Leave it in the open.
The air we breathe contains some oxidising agents, as oxygen is the most widespread. When cannabis is exposed to oxygen, a reaction at the molecular level changes the plant’s cannabinoid structure.
The same 1999 study that determined to fast of THC degradation over four years found that the deterioration of THC was related to an increase in cannabinol (CBN) levels. This is because when oxidised, THC converts to CBN.
CBN is a non-psychoactive cannabinoid that, although indicative of an ancient herb, has some therapeutic utility. CBN is believed to play a significant role in the sedative effect that cannabis has on users. This makes it a valid treatment for insomnia. Furthermore, CBN exhibits antibacterial, anti-inflammatory, appetite-stimulating, analgesic and glaucomatogenic attributes. Since the only way to obtain CBN is through the oxidation of THC, this could be the only incentive to accelerate the THC degradation process. However, CBN is much less potent than THC and CBD, both with similar therapeutic capabilities and capable of reaching them in much smaller dosages.
3- High temperatures for an extended period.
Ironically, heat is also an essential ingredient in the synthesis of THC. The raw cannabis flower does not contain THC. Instead, it is loaded with THCA, the acid and inactive precursor of THC. THCA does not produce the psychoactive effect that THC has.
THCA becomes THC during the decarboxylation process, or exposure of grass to heat for a specified period. Cannabis and Cannabinoid Research has published a 2016 study that studies the time and precise temperatures for the most efficient decarboxylation processes. According to this research, all THCA was synthesised at THC after the raw cannabis was heated to 110 degrees C for 30 minutes, 130 degrees C for 9 minutes, or 145 degrees C for 6 minutes. However, as soon as the decarboxylation was completed, THC levels began to deteriorate.
Using these three mixed methods or one only the thc level (but also cbd) of your plants will tend to lower in percentage to the original level, undoubtedly a thc level of 0.75 / 0.80% can easily be reduced below 0,6% while maintaining the quality of your inflorescences intact. Discover the CBG precursor of THC and CBD Sources: the scientific data used as from the NBCI National Center for Biotechnology Information