Scientists Sniff Out What Gives Marijuana Strains Their Distinct Aromas, Revealing How Terpenes And Other Compounds Interact

Researchers have conducted the first comprehensive sensory-guided study of
the odor-active compounds in dried cannabis flowers, uncovering dozens of
previously unknown chemicals that shape the the plant’s distinct fragrance.
The findings expand scientific knowledge of marijuana beyond the common
understanding of terpenes, CBD and THC.

To unravel the chemistry of smell, the researchers utilized a sensory
guided technique that is more familiar in food science than cannabis
research. Using a gas chromatography-olfactometry device along with aroma
extract dilution analysis, they cataloged the volatile compounds in
marijuana and, importantly, explored which ones actually matter to the nose.

“By means of this methodology, it was proven that only a small fraction of
the volatiles contributes to the overall aroma perception,” the researchers
wrote.

The method worked by diluting the volatile compound mixture and having
trained assessors assign each compound a “flavor dilution factor” that
reflected its potency. By pairing chemical analysis with human sensory
testing, the researchers identified 52 odor-active compounds, including
terpenes, esters, sulfur molecules, phenolic compounds, volatile acids and
furanones.

Notably, 38 of these odorants had never before been reported in dried
marijuana flowers, and six had not been detected in any cannabis material
until now.

“The presence of these new odor-active components further supports the idea
that certain odorants may be formed or released during drying and curing,”
they wrote. “Future research is needed to explore how enzymatic or
oxidative pathways contribute to these transformations.”

“The present study provides the first comprehensive sensory-guided
investigation into the composition of the odor-active compounds of dried
hemp flowers, revealing the intricate interplay between terpenes, esters,
sulfur compounds, and previously underexplored odorants such as phenolic
compounds, volatile acids, and furanones.”

The work could open the door wider for novel cannabis breeding. Just as
wine or coffee tasting hinges on subtle aromatic compounds, marijuana can
be described in equally nuanced sensory terms.

For the study, scientists paired odorants with perceived fragrance
qualities.

For example, they note that a sweaty smell emanating from cannabis is due
to butanoic acid, hexanoic acid and 2-methylbutanoic acid. A popcorn smell
is associated with 2-acetylpyrazine. For consumers seeking an earthy, bell
pepper-like smell, 3-isobutyl-2-methoxypyrazine is the odorant causing the
scent. An oatmeal-like, sweet scent comes from
(2E,4E,6Z)-nona-2,4,6-trienal or α-terpineol for floral and citrus notes.

Additional odor qualities included fruity, pine-like, terpene-like,
hop-like, mushroom-like, musty and clove-like, among others.

The findings reenforce a key point relevant to cannabis industry
professionals that most have long known or suspected. Aroma may be the
strongest predictor of consumer appeal, which is why breeders already
select cultivars for scent as much as for CBD or THC levels.

In the past, research largely focused on fresh marijuana flowers or
THC-rich varieties, leaving dried cannabis under-explored. By adapting
tools commonly used in food science that identify which volatiles truly
shape aroma perception, the researchers in the current study provided the
clearest picture yet of what gives marijuana its unique smell. Scientists
used freeze-dried cannabis flowers of six cultivars provided by Puregene AG
in Switzerland.

The authors, affiliated with the Zurich University of Applied Sciences and
the Technical University of Munich, said their study “lays the first
groundwork for understanding the odorant composition of dried marijuana
flowers, providing a basis for future validation through quantitation and
aroma reconstitution studies,” common methods in food science research.

“By deepening the knowledge of cannabis secondary metabolism, targeted
breeding efforts could optimize the production of desirable odorant
compounds, catering to distinct market preferences in food, fragrance, and
cannabis-based consumer products.”

The paper was published by the American Chemical Society and appears in the
September 2025 issue of the Journal of Agriculture and Food Chemistry, a
peer-reviewed journal.

The study found that while well-known terpenes such as α-pinene, myrcene,
and linalool played major roles, the analysis revealed that
sulfur-containing molecules notorious for their pungency also strongly
contribute to marijuana’s scent. Compounds like 3-methylbut-2-ene-1-thiol
and 4-methyl-4-sulfanylpentan-2-one were detected in dried flowers at a
high potency for the first time.

The new paper builds on research related to standardization of cannabis
strain identification. In 2022, researchers found that the commonly used
marijuana strain labeling system can be highly misleading for consumers.
The study analyzed the chemical composition of almost 90,000 cannabis
samples across six states.

Research earlier this year on cannabis genetics suggested that incentives
in the legal marijuana market—such as the desire for plants to mature
faster and produce more cannabinoids for extraction—may be leading to a
decline in biodiversity of the plant worldwide.

This paper also builds on a July 2025 scientific review in the journal
Molecules that took a deep dive into the flavors and aromas of marijuana,
examining how the plant’s genetic makeup, cultivation methods and
post-harvest processing affect the various compounds that give cannabis
products their distinctive palate.

The post Scientists Sniff Out What Gives Marijuana Strains Their Distinct
Aromas, Revealing How Terpenes And Other Compounds Interact appeared first
on Marijuana Moment.