Finally Discovered: The Chemicals Responsible for Marijuana’s Funky Scent
Scientists have finally figured out the sulfur compounds in the cannabis flowers that give it that distinctive odor.
The signature aroma that you’ll smell on fresh weed isn’t a single molecule or compound. Instead, it is a cocktail of hundreds of compounds with different fragrances. A common class of molecules known as terpenes is responsible for the most outstanding floral, pine, and citrus-like overtones. This is according to an analytical chemist, Lain Oswald who works at Abstrax Tech, a private company in Tustin, California, that works on terpenes for various cannabis products.
However, the source of the impossible-to-miss funky note of weed has been almost impossible to pin down all along – well, until now.
A recent analysis now takes credit for the first identification of a group of some sulfur compounds in cannabis that are responsible for the skunky scent. The researchers reported the findings on November 12 in ACS Omega.
Oswald and his colleagues suspected that the culprit did contain sulfur, which is a stinky element found in both skunk spray and hops. Therefore, the team began by rating the skunk factor of the flowers taken from over twelve cannabis varieties while on a scale of zero to ten with ten being the most pungent. They then crafted the chemical fingerprint of the airborne substances responsible for the unique scent of each cultivar by use of gas chromatography, a sulfur chemiluminescence detector, and mass spectroscopy.
And just as they suspected, they found trace amounts of a few fragrant sulfur compounds in the profiles of the cultivars with the heaviest scents. They found a molecule known as prenylthiol or 3-methyl-2-butene-1-thiol to be the most dominant, therefore responsible for the notorious ‘skunked beer’ flavor.
According to Amber Wise, sulfur compounds have been known to occur in nature but weren’t expected to be found in cannabis. Wise is a Medical Creek Analytics analytical chemist in Fife, Washington.
The researchers were surprised to find that prenylthiol and the rest of the sulfurous culprits in cannabis have some structural similarities with some molecules in garlic. Apparently, the little quantities go a long way.
According to Oswald, even when these compounds occur in low concentrations on the flower, they still have significant impacts on the smell. When the cannabis flowers achieve maturity and as they’re in the curing process, the sulfur molecules are at their most abundant.
Avery Gilbert is a smell psychologist of Headspace Sensory, which is a startup company in Fort Collins, Colombia that focuses on quantifying the various scents in cannabis. He expresses his excitement as he waits to see the molecules added to the chemical repertoire of Marijuana. He barely conceals his zeal as he adds that he considers the spectrum of the cannabis odor so amazing that it “beats the pants off of wine.”
Gilbert says that the discovery of prenylthiol in cannabis is the first step to maximizing its inexplicably pleasant stink – or masking its unpleasant odor.
Oswald opines that prenylthiol has a polarizing scent. He says that some people think that cannabis stinks, while others are willing to pay more for the skunkiest grass as they consider it a sign of quality. Cannabis producers will design the packaging print according to the smell quality of different strains.