That skunky smell? Blame ‘321 MBT’ and not Terpenes

[Cvh]

https://hemptoday.net/that-skunky-smell-blame-321-mbt/

American researchers say they have determined what gives cannabis its skunky smell. Scientists from Indiana-based Byers Scientific and Iowa State University say the compound 3-methyl-2-butene-1-thiol (“321 MBT”) is the main source of the odor, and not cannabis plant terpenes, which have generally been considered to cause the smell. The research team used analytical chemistry, leaf enclosure study and field observation to isolate and identify the aroma’s source. 321 MBT is the same chemical that causes the skunky-like aroma in spoiled beer, the scientists said. Hops, the main ingredient in beer, is also of the Cannabaceae plant family. The research is part of efforts to devise ways to eliminate the smell.

 

[Cvh]

Anybody any more info or comments?

 

[...CR500AF...]

Nothing to add but thx for the info, for places that are still illegal this would be great to find out how to lose the smell, cool info...

 

[Gaussamer]

The research is part of efforts to devise ways to eliminate the smell.

Figures.

 

[Maple_Flail]

haven't we been there and done that.. realized it wasn't a good idea as pot that doesn't smell at all in my experience, may have been frosty but the effect are totally sub par.

the smell is part of the entourage effect. where ever it comes from, there is a noticeable lack of effect similar to using pure distillate and isolate in edibles. the effects are flat, there are breakpoint plateaus.. and you generally need more to get where your going vs full spectrum.

If smell is an issue, then they are cutting corners of overgrowing numbers and want to hide it easier. simple as that. this isn't the 80's where there wasn't a grow shop on just about every corner in legalized areas. getting access to decent carbon filtering isn't hard these days..

research money is better spend else where IMHO.

 

[CannaRed]

I believe the research is to remove the skunky smell from beer, not cannabis.
They just figured out that the same compound was also in cannabis. I dunno, I may he wrong.

 

[CannaRed]

At this site you can order standards to train your nose on how to recognize the odor of skunky beer
https://www.aroxa.com/beer/beer-flavour-standard/3-methyl-2-butene-1-thiol/

 

[CannaRed]

Notice they describe the odor as "Lightstruck, like a skunk or freshly-brewed coffee”

My wife says I'm crazy but I've always thought that when the coffee first starts brewing that it smells skunky.

 

[Cvh]

https://www.cannabissciencetech.com/...nts-identified

Chemical Compound Causing Cannabis Odor Complaints Identified

Researchers from Byers Scientific, Iowa State University, and Texas-based odor experts identified the odor of cannabis.

A research team comprised of Byers Scientific, Iowa State University (Ames, Iowa), and Texas-based odor experts recently reported the isolation and identification of a volatile chemical that might be the cause for the downwind skunky-like environmental odor complaints that have commonly plagued commercial cannabis and industrial hemp growing operations (1).

Through the use of a triangulation approach of analytical chemistry (such as solid phase microextraction [SPME] fiber, gas chromatography-mass spectrometry [GC–MS], and GC-olfactometry analysis), a leaf enclosure study, and field observation, researchers were able to isolate, identify, measure, and figure out that the compound 3-menthyl-2-butene-1-thiol (321 MBT) is the primary source of the cannabis odor. The compound is also the same odorous chemical previously reported to carry the responsibility for the skunky-like aroma and flavor defect in light-struck beer.
​​​​​
This odor of cannabis has often been tied to terpenes. The newly reported discovery of the link between “skunky’”cannabis and 321 MBT supports the assumption of a sulfur component within the chemical profile of the cannabis plant emission. In hindsight, the newfound link between “skunky” beer and cannabis should not be all that surprising because the “skunky” beer odor originates from hops, which are in the same plant family (Cannabaceae) as cannabis and hemp. Prior odorant efforts by the researchers has shown MBT to represent an odor impact priority for actual skunk oil, as extracted from the skunk musk gland. In previous investigations, MBT was adjudged as second in odor impact priority, second only to E-2-butene-1-thiol.

Even with the fascinating news of identifying the compound of cannabis’s odor, the researchers still urge for caution as this is only the first critical step in fully researching the issue. Leaf enclosure studies have disclosed other thiols present in the plant emissions, other compounds in the plant’s gas-phase emissions, and that atmospheric reactions may significantly affect the perception and measurement of 321 MBT. There are further research efforts underway to dig deeper into the evaluation of the odor and the most appropriate manner of mitigation.

Reference
https://www.prnewswire.com/news-rele...301254409.html

 

[troutman]

I don't think indoor gardens will produce much Thiols. Been doing RKS research for a while now.

Outdoors is where it will happen if at all with the right genetics and soil components.

3-methylbut-2-ene-1-thiol = Odor Description: Intense leek, onion-like, skunky.

 

[f-e]

There is a common smell, but it's not the main component in our greens smell. Usually I don't smell it at all, but the french onion leaf might be a good description, when it's on your hands, with a little 'old copper coin' in the mix.

 

[Hashmasta-Kut]

Thiol compounds, been saying this for years. Read it on a weed site about 7 years ago I'd reckon. I have experienced real skunky skunk first hand for decades and propane. Both stink like crazy, both have mercaptans that break down to thiol compounds.

 

[Hempy McNoodle]

The first time I ever smelled "marijuana" smoke was at a Black Sabbath concert in San Francisco when I was 11 years old. These dudes were sitting in the row in front of me and they were smoking up this big fucking cigar of pot. I remember the smell,.. straight up dog shit! What causes the dog shit smell? By the way, I used to get weed all the time in the 90s that smelled just like skunk and LOUD! It would smell up an area so bad!

 

[Cvh]

I don't think indoor gardens will produce much Thiols. Been doing RKS research for a while now.

Outdoors is where it will happen if at all with the right genetics and soil components.

3-methylbut-2-ene-1-thiol = Odor Description: Intense leek, onion-like, skunky.

What's the reason that indoor gardens don't produce much thiols?

I personally grow full organic in soil indoors that has amendments like Lava Meal,...etc. It's loaded with secondary (ie. sulfur and such) and micro nutrients, it's also teaming with good biological life.
Do you think my plants -given the correct genetics- would produce thiols?

Or are you referring to hydro grows which lack in the secondary macro and micro nutrients and don't contain any or not much rhizosphere life?

What would be required for a plant to be able to produce Thiols?
​​​​​​

 

[troutman]

What's the reason that indoor gardens don't produce much thiols?

I personally grow full organic in soil indoors that has amendments like Lava Meal,...etc. It's loaded with secondary (ie. sulfur and such) and micro nutrients, it's also teaming with good biological life.
Do you think my plants -given the correct genetics- would produce thiols?

Or are you referring to hydro grows which lack in the secondary macro and micro nutrients and don't contain any or not much rhizosphere life?

What would be required for a plant to be able to produce Thiols?
​​​​​​

Well for one thing. Thiols smell very strong and I don't think anyone will want
to live with that aroma indoors. It would drive you mad or sick in no time.

https://en.wikipedia.org/wiki/Thiol

The simplest thiol is methanethiol and it's toxic. You can smell it at 1 part per billion (ppb)
and it's used to odorize natural gas and propane so you know there's a leak. If you had the
thiol aroma indoors people may come looking for a gas leak.

https://en.wikipedia.org/wiki/Methanethiol

 

[Cvh]

troutman
​​​​​​​Ok, but that's not really answering my questions why you say that indoor gardens aren't capable of producing much thiols?

 

[Agronomist]

troutman
Ok, but that's not really answering my questions why you say that indoor gardens aren't capable of producing much thiols?

Maybe you have less sulfur in your soil?
Or less sulfur in your fertilizer.

 

[Maple_Flail]

troutman
Ok, but that's not really answering my questions why you say that indoor gardens aren't capable of producing much thiols?

from a brief glance with merely observational eyes, I would suspect there is an interaction that would be atleast tricky to replicate indoors consistently.

seems to be a yeast/bacteria interaction with the sulfur in soil causing a break down product that once the plant ingests feeds the pathway to these thiols.

 

[Hashmasta-Kut]

troutman
Ok, but that's not really answering my questions why you say that indoor gardens aren't capable of producing much thiols?

Most stuff has 0 thiols present. Skunk grown indoors stinks to high heaven, and no stinkier outdoors.

 

[Hashmasta-Kut]

I don't think indoor gardens will produce much Thiols. Been doing RKS research for a while now.

Outdoors is where it will happen if at all with the right genetics and soil components.

3-methylbut-2-ene-1-thiol = Odor Description: Intense leek, onion-like, skunky.

Not true really. Skunk is extremely skunky indoors. Nothing to do with soil, only genetics.