Skunky Cannabis: Environmental Odor Troubleshooting and the Need-for-Speed

Although the skunky odor characteristic of cannabis has been widely referenced, its cause has been historically misassigned to unspecified skunky terpenes. Recent reports from two independent research groups, the Koziel team (March and April 2021) and Oswald team (August and November 2021), have corrected this misassignment by linking the skunky character of industrial hemp and cannabis to 3-methyl-2-butene-1-thiol (321MBT). A recent USPTO patent application review clearly indicated that the Oswald team should take full credit for the discovery of this link with respect to cannabis. However, the August 19, 2021 publication of their patent application appears to be their formal public disclosure of 321MBT as the primary source odorant which is responsible for the targeted skunky odor. This date is well after the March and April 2021 public disclosures by the Koziel team for the 321MBT/skunky odor link relative to both cannabis and industrial hemp. This Viewpoint summarizes the investigative strategy leading to the public disclosure of this historically elusive link. It is presented from the perspective of the rapid multidimensional-gas chromatography-mass spectrometry-olfactometry (i.e., MDGC-MS-O) based odorant-prioritization screening approach, as applied by the Koziel team.

Automated summary

Although the characteristic skunky odor of cannabis has long been discussed, its cause has been mistakenly attributed to unspecified skunky terpenes. Recent research has corrected this misperception and identified 3-methyl-2-butene-1-thiol (321MBT) as the primary compound responsible for the skunky odor in both industrial hemp and cannabis.