Why Does Cannabis Smell Like Skunk? What Aroma Research Suggests

Open a fresh jar of cannabis flower in New York and the first thing you notice is not a number. It is the smell. For decades the explanation offered at counters and in strain guides was simple: terpenes. Myrcene for earthiness, limonene for citrus, pinene for the forest. Terpenes are real and they matter, but a series of chemistry and sensory studies published from 2021 onward suggests they are only part of the story, and that the signature skunk note comes from trace compounds working alongside them.

The research points to a small group of sulfur compounds and other trace molecules, present in tiny amounts, that appear to carry an outsized share of the aroma. Here is what the studies indicate, why it matters for how flower is labeled in New York, and what it may change about how you shop by nose.

The Compound Behind the Skunk

The clearest answer to why cannabis smells like skunk came from a 2021 paper in ACS Omega.^[1] Researchers used comprehensive two dimensional gas chromatography, a technique sensitive enough to pick out compounds that conventional testing misses, to analyze flower from 13 cultivars. A small panel ranked each sample for pungency on a scale of zero to ten.

The team identified a previously undescribed family of volatile sulfur compounds in cannabis. Several of them share a chemical feature called a prenyl group, and the most abundant in the most pungent samples was 3-methyl-2-butene-1-thiol, which the authors labeled VSC3. Brewers already know this molecule. It is associated with the off aroma of beer that has been exposed to light, often described as "skunked."

The researchers then ran a simple test. They blended VSC3 into a mixture of ten major cannabis aroma compounds and reported that the result smelled very similar to the characteristic cannabis scent. Without it, the terpene mixture alone did not get there. That finding suggests the signature skunk note rests on a sulfur compound present at trace levels rather than on the terpenes that dominate a lab report. Like the 2023 follow-up below, this paper came from researchers at Abstrax Tech, a California terpene and flavor company, and three of the authors have filed a patent related to the findings.

Timing, Curing and Storage

The same study tracked these sulfur compounds through late flowering, curing and storage in one indoor greenhouse trial of four clones of a single variety, and the pattern is worth knowing. Levels rose significantly toward the end of flowering, peaked during curing, and then dropped substantially after about ten days of storage.

That is a single study and its storage window was short, so it should not be read as a precise shelf life. Still, it lines up with what earlier work on storing flower and keeping it fresh already suggests: the most volatile parts of the aroma are also the most fragile. A jar that smells muted may have lost compounds that never appeared on its label in the first place.

Beyond Skunk: The Sweet, Savory and Tropical Notes

Skunk is only one register. Many of the cultivars people describe today lean sweet, citrus, tropical or savory, with notes some consumers compare to garlic or fuel. A 2023 follow-up study in ACS Omega, from several of the same researchers, set out to explain those.^[2]

The team analyzed 31 samples alongside a sensory panel and compared their chemistry with how each one was described. The terpene results were the surprise. Profiles were remarkably similar across very different smelling varieties, with an average correlation of 0.65 for monoterpenes and 0.84 for sesquiterpenes. Limonene and myrcene showed almost no relationship to how distinctive a sample was rated.

What did track with distinctive aromas were minor, nonterpenoid compounds. A class of sulfur compounds containing a 3-mercaptohexyl group lined up with citrus and tropical notes. A compound called skatole tended to appear in savory and chemical smelling varieties. Esters and other flavor molecules correlated with higher distinctive-aroma scores. Many of these compounds made up less than 0.05 percent of a sample by mass.

The authors wrote that their results show the importance of terpenes to cannabis aroma "has been overemphasized." Three caveats apply. The sample was small and drawn from one region; the samples were ice hash rosin, a solventless extract, rather than flower; and the work was funded by Abstrax Tech, the terpene and flavor company where most of the authors work, while eight of the authors have filed patents related to the results. It is a meaningful finding, not a closed case.

A Shared Vocabulary for Cannabis Aroma

If chemistry alone does not explain aroma, describing it carefully becomes more important. A 2025 study in PLOS ONE from Oregon State University proposed a 25 term lexicon for the aroma of cannabis flower.^[3] Trained panelists smelled 91 samples of intact, unburned flower, 32 THC-dominant and 59 CBD-dominant hemp, and selected every descriptor that applied.

Four broad aroma groups emerged: fruity, berry and sweet; citrus and chemical; cheesy and barnyard; and a skunky, earthy and musty group, made up mostly of THC-dominant flower, that also took in fuel, black tea, straw and toasted bread notes. The team then checked whether lab data could predict those groups. Their summary was direct: "terpene chemistry alone does not predict a sample's sensory profile." The team could measure sulfur compounds only in the CBD-dominant hemp samples, and those data did not predict the groups either. The authors attribute part of that to sample size and call for more work on the effects of drying, storage and trimming.

Read together, the three studies suggest that aroma is the product of many compounds interacting, some of them barely measurable, and that the nose is still a better instrument than any single number on a lab report.

What This Means for New York Labels

New York requires every cannabis product to be tested for terpene content. The Office of Cannabis Management sets a minimum testing panel that includes beta-myrcene, beta-caryophyllene, limonene, alpha-pinene, linalool and terpinolene, among others.^[4] When terpenes are marketed, a New York label must carry a terpene profile.^[5] That panel is genuinely useful, and it is far more informative than a THC percentage on its own.

The research above adds a layer. The sulfur compounds and trace molecules most associated with skunk, tropical and savory notes are not part of the required panel, and measuring them takes specialized equipment. So two jars with near identical terpene panels may still smell quite different, which is consistent with the finding that cannabis produces far more aroma compounds than any label lists.

Shopping by Nose

None of this makes the label less worth reading. It suggests reading it alongside your own senses. A few habits follow from the research:

• Read the terpene panel as a map of the main aroma families, not a full description of the smell.
• Ask how recently a product was packaged, since the most distinctive aroma compounds appear to fade first.
• Describe what you like in plain aroma words, such as citrus, gas, berry or earth. Those descriptors may say more than a chemical name.
• Keep flower sealed, cool and out of light once you open it.

That is why the strain pages for our newest batches list the leading terpenes from the batch lab report: the profile starts the conversation, and the jar finishes it.

References

1. Oswald IWH, Ojeda MA, Pobanz RJ, et al. Identification of a new family of prenylated volatile sulfur compounds in cannabis revealed by comprehensive two-dimensional gas chromatography. ACS Omega. 2021;6(47):31667-31676. doi:10.1021/acsomega.1c04196
2. Oswald IWH, Paryani TR, Sosa ME, et al. Minor, nonterpenoid volatile compounds drive the aroma differences of exotic cannabis. ACS Omega. 2023;8(42):39203-39216. doi:10.1021/acsomega.3c04496
3. Isaacson SE, Wilson-Poe AR, Ye T, Qian YL, Shellhammer TH. Beyond potency: a proposed lexicon for sensory differentiation of Cannabis sativa L. aroma. PLOS ONE. 2025;20(10):e0335125. doi:10.1371/journal.pone.0335125
4. New York State Office of Cannabis Management. Cannabis Testing Limits, revision February 9, 2026. cannabis.ny.gov
5. New York State Office of Cannabis Management. Adult-Use Packaging and Labeling, 9 NYCRR Part 128, § 128.5(b)(10), as amended effective December 3, 2025. cannabis.ny.gov