In the last Testing for Truth article, we blasted some cannabis with a solar simulator, and found that very little D9THC or CBN production took place. That test had us asking the question, what happens to really old cannabis? Does it contain mostly THCA? Is there any CBN present? Fortunately, we had access to a 10-year-old sample and decided to put this to the test to see what cannabinoids were still lurking in this old cannabis.
We prepared the 10-year-old cannabis sample as well as a 2.5 year old sample. Neither sample was exposed to significant light, heat or humidity during storage, so despite their age, the samples were treated reasonably well. Both samples along with a control fresh cannabis plant were homogenized and analyzed on a LightLab analyzer, which measured the levels of 6 cannabinoids.
The three graphs at the bottom of this article show that there was definitely some decarboxylation of THCA (the cannabinoid that the plant generated) into D9THC. The further degradation into CBN also occurred. Interestingly, the most abundant cannabinoid was still THCA. We believe this was in part due to the fact that samples were stored in close to ideal conditions for the entirety of the test. The amount of D9THC and CBN were both relatively higher in the oldest sample, and nearly nonexistent in the fresh sample. Total cannabinoid levels were quite low in both samples. This could mean low potency cannabis to start with, or more likely some of the cannabinoids are simply destroyed completely. One other interesting thing we noted: there was an unknown component identified in both the 2.5-year-old and 10-year-old sample, with the 10-year-old sample showing a stronger signal.
For those of you that are chromatography experts, this peak elutes earlier than any common cannabinoid on a reverse phase column. We are not sure what this component is yet, but it could be another breakdown component of the cannabinoids, or an unidentified cannabinoid. We will be working to try to discern what exactly this mystery component is in the coming months. If anyone has suggestions we would be happy to hear them!
In summary, these tests suggest the following:
THCA does decarboxylate into D9THC as cannabis ages
CBN is generated as cannabis ages, albeit at low levels
The amount of CBN and D9THC depend on how long the cannabis has aged
A mystery compound is generated in the aging process
While it’s probably best to consume your cannabis in a reasonable amount of time, it looks as if there are still at least some cannabinoids in that old bag hiding in your closet.