Skunk Notes

Why cannabis smells skunky

Dec 2021, phys.org

https://phys.org/news/2021-12-cannabis-skunky.html

Finally, move over terpenes, the real smell of cannabis is here -- a new family of prenylated volatile sulfur compounds (VSCs), aka "skunk" is found in dank buds. 

Of the VSC varieties, 3-methyl-2-butene-1-thiol (VSC3) was the skunkiest. And of the 13 strains of cannabis tested, Bacio Gelato was the skunkiest.

via American Chemical Society: Iain W. H. Oswald et al, Identification of a New Family of Prenylated Volatile Sulfur Compounds in Cannabis Revealed by Comprehensive Two-Dimensional Gas Chromatography, ACS Omega (2021). DOI: 10.1021/acsomega.1c04196

http://dx.doi.org/10.1021/acsomega.1c04196

Post Script:

Don't forget that dank smells does not mean potent pot, yet people associate citrusy-sweet-sour aroma with more THC:

Gilbert AN, DiVerdi JA (2018) Consumer perceptions of strain differences in Cannabis aroma. PLoS ONE 13(2): e0192247. https://doi.org/10.1371/journal.pone.0192247

https://doi.org/10.1371/journal.pone.0192247

And, from a separate study, it was noticed that the genetic, terpinoid and cannabinoid profiles of selected strains didn't match their descriptions as either Sativa or Indica. Instead, it looks like people just name them whatever they smell like, sweet for Sativa and earthy for Indica:

S. Watts et al, Cannabis labelling is associated with genetic variation in terpene synthase genes, Nature Plants (2021) DOI: 10.1038/s41477-021-01003-y

https://doi.org/10.1038/s41477-021-01003-y

Can't leave without this; why does natural gas smell somewhat skunky? It's been odorized on purpose since a big explosion that killed almost 300 people in the 1930's:

49 CFR, Part 192:Transportation of Natural and Other Gas by Pipeline: Minimum Federal Safety Standard, Subpart L: Operations, 192.625 - "Odorization of Gas"

Are Terpenes the New Antioxidants, 2018

http://www.limbicsignal.com/2018/09/are-terpenes-new-antioxidants.html

Roses Really Do

OutKast – Roses – 2003

video link

It’s true. Roses really do smell like the end product of our metabolism. Two major constituents of the smell of roses are Skatole and Indole, which are good olfactory representatives of excrement. They’re also used extensively in perfume.

This may or may not explain why many air fresheners (at least as far as I know since the dawn of aerosolized air fresheners) smell like roses. Regardless of whether shit and flowers go together like peanut butter and jelly, it was used a lot as an air freshener scent, at least as far as the early 90’s. (Anyone like to weigh-in here on the history of air fresheners?)

But this fact does explain why I, among others I’m sure, hallucinate excrement when smelling roses – you expect it to be there. This is called redintegration, a kind of hallucination, and it’s explained in this clip from Hidden Scents:

Part of a smell can carry with it the co-occurring odor molecules around them in the memory, and it will later be used to substitute for the whole. Strains of cannabis, aside from the strong skunk-like smell, can have significant amounts of limonene in them. Through redintegration, the potent smells of such cannabis become so tied together that upon smelling an orange (almost entirely limonene), a frequent user might hallucinate the other odors of cannabis along with the orange. This phenomenon represents an apparition superimposed in order to satisfy the nose-brains’ insistence on predicting an odor based on limited or partial information – a behavior that is not limited to olfactory perception.

Post Script

The scent of “musk” comes from the neither region of the musk deer. Just saying. Today you wouldn’t know that, because that scent of musk is now more associated with fresh laundry. Musk is a very big molecule, for a smell, and it sticks really well to your clothes even as they’re being washed, so it’s the main ingredient in laundry detergents.

When you smell “clean laundry,” you don’t think you’re smelling musk, but you are. Funny how today we associate clean with a thing that ultimately comes from an animal’s butt. (Please note that today, most if not all musk comes from a laboratory and not an animal.)