Skunk Smell in Cannabis
A couple months ago, I decided to do some casual coffee shop reading in the form of a ten-page scientific paper titled, Identification of a New Family of Prenylated Volatile Sulfur compounds (VSCs) in Cannabis. Why might you be wondering? This is an aromatic breakthrough in the cannabis industry!!! This report has found a new family of chemical compounds responsible for the signature unmistakable skunk smell in cannabis! I broke down the information in my Instagram highlights but decided it was time to put together a blog on the topic. Think of it like my version of CliffNotes for Potheads.
What I love about scientists is that they were like, "People say cannabis smells like a skunk, so let's do a test that measures the compounds in skunk spray and other similarly odorous materials like Durian and see what happens." #hypothesis. Spoiler, it worked! The scientists discovered all these VSCs or volatile sulfur compounds, some of which had never been identified in nature!
They took this information and formulated the floral aroma profile of a Gelato cultivar using botanically derived isolated terpenes in a lab and concluded yeah, that's the smell. But science doesn't stop there. Further testing was conducted with a variety of cannabis samples. This included a controlled greenhouse trial with four OG varietal clones grown, dried, and cured exactly how commercial cannabis is grown. Even going so far as to use glass mason jars to cure the flowers and collect weekly aroma samples using a headspace vial. The samples were analyzed using gas chromography to confirm the presence of these VSCs in the OG flowers throughout the growing and curing stages.
Part two of the experiment involved a panel of four olfactory experts rating the pungency of 13 different cultivars on a scale of 1-10 to identify trends between aroma characteristics and individual compounds. 10 begin the most pungent and 1 being the least. They found the two strains with the most significant aroma differences were Baccio Gelato, at a 10 on the scale, and Black Jack, at 1. They cross-referenced the panel evaluations with GCxGC-SCD chromatographs (a super next-level aromatic molecular compound measuring). Which showed that the intense peaks found in BG were utterly absent. This indicated that the BG had many more VScs than the BJ. They began to look at the chromatographs and started isolating the VSCs into molecular categories from 1-7. Each VSC was given an aromatic profile from the panel of experts. This is the most exciting part of the report's observations for me.
VSC1: sulfurous, vegetable, cabbage
VSC2 fatty, winey
VSC3: intense, sulfurous, skunk-like
VSC4: intense sulfurous, savory
VSC5: intense sulfurous skunk-like
VSC6 & VSC7: mild alliaceous
The scientists now have all the VSCs and their respective aromas and molecular makeup. They found that these exact molecules were also found in the defensive secretions of skunks and beetles, as well as garlic and onion, and have scientifically confirmed their presence in WEED.
VSC3 was of particular interest because its potency, even when extremely diluted, contributes strongly to the skunk scent of cannabis.
So here are the final results of this research:
There is a correlation between VSC3 concentration and the aromatic characteristics of skunk in cannabis.
Product age significantly affects the concentration of VSCs (as discovered in the indoor OG greenhouse experiment). After about a month and a half, most VSCs pass off as vapor, like terpenes.
Packaging plays an important role. An older sample packaged in a plastic jar with an airtight aluminum seal demonstrated a higher concentration of VSCs compared to its age. The samples in zip locks did not contain the VSCs.
And lastly: plant growth conditions and genetics are likely more conducive to VSC production, specifically relating to environmental stressors.
In the final test, they tried to reverse engineer the Baccio Gelato in one round with its top 10 components. It was close but not quite right, so they added VSC3, which resulted in an immediate olfactory change that strongly emulated the flower's scent. Basically, SKUNK or VSC3 was the missing ingredient.
Interestingly, they left a bit of a cliffhanger at the end of the report, referencing the health benefits of onions and garlic could potentially relate to these VSC compounds. Further research is needed, but is it possible that these vegetables' anticarcinogenic, cancer-protective, and cardiovascular health properties could relate to the VSCs? And if so, might these properties also be present in cannabis?
Read the full report here: