The Cannabis Story a Percentage Cannot Tell

 Imagine two jars of cannabis flower sitting side by side. One carries a higher THC percentage. The other has a distinctive aroma: citrus peel, something woody, a sharp note that is difficult to name. Which one tells the more interesting story?

A percentage offers an immediate answer to a narrow question: concentration. Everything else takes more investigation. What creates that smell? Does a familiar strain name reliably identify what is inside? How much can a laboratory report explain about something people experience through their senses?

Those questions are drawing researchers into territory that cannabis marketing often compresses into a number or a catchy name. Their findings reveal a plant whose character is considerably more complicated than its most famous ingredient.

For Canadian Seed Bank readers, this is where cannabis becomes especially interesting: at the meeting point of genetics, chemistry, human perception and the stories attached to particular varieties.

What THC Can Actually Tell Us

THC deserves attention. Health Canada identifies it as the substance primarily responsible for cannabis intoxication. Its effects can include impaired attention and memory, and some people experience anxiety or panic. Discussing aroma and diversity does not make potency irrelevant; concentration remains meaningful information with real implications. Health Canada.

A potency figure measures one aspect of a product. Health Canada’s label guidance explains that “Total THC” represents the THC available when the product is heated. It does not give the product a score for aroma, establish its ancestry or promise a particular personal experience. Reading that number accurately is useful; asking it to answer unrelated questions is where confusion begins. Health Canada’s cannabis label guide.

When Researchers Put Aroma to the Test

One intriguing challenge to potency as a stand-in for quality appeared in a 2022 study published in Psychoactives. Researchers analysed anonymous reports from volunteers evaluating cannabis flower in competitions. Samples were distributed under blinded conditions, reducing the influence of knowing a product’s identity beforehand.

Pleasant aroma was associated with pleasant subjective effects. THC potency, by contrast, was not associated with overall subjective appeal in the analysis. Neither was the total amount of terpenes measured. Plumb and colleagues, 2022.

The finding is provocative, but its boundaries matter. This was an observational analysis involving competition participants, rather than a clinical trial proving that a particular smell causes a better experience. It cannot establish what every consumer will prefer.

What it does offer is a reason to question the assumption that increasing one laboratory number automatically improves the experience being judged.

The Chemical Mystery Behind the Skunky Smell

The discovery behind cannabis’s unmistakable skunky note reads almost like a chemical detective story.

In 2021, researchers reporting in ACS Omega identified a family of volatile sulfur compounds associated with that characteristic scent. One compound, 3-methyl-2-butene-1-thiol, emerged as the principal contributor. The important detail is its chemical family: the explanation lay beyond the terpenes that usually dominate conversations about cannabis aroma. Oswald and colleagues, 2021.

The researchers used sophisticated analytical equipment to separate and identify aromatic compounds. They also tracked the sulfur compounds over time, finding that their concentrations changed during development and after harvest. In that experiment, concentrations rose late in flowering, peaked during curing and subsequently declined in storage.

That gives the familiar smell another dimension. Aroma reflects chemistry that can change over time. It is not simply a permanent feature captured by a strain name. The findings also explain why discussing cannabis scent solely through a short list of dominant terpenes leaves part of the story untold.

What Is Really Behind a Strain Name?

A separate line of research has investigated the names themselves. “Indica” and “sativa” are among the most recognisable words in cannabis, but how closely do those labels match the plant’s underlying biology?

A 2021 study in Nature Plants, involving researchers at Dalhousie University and collaborators, examined chemical data from 297 samples and genetic data from 137 of them. Samples carrying indica and sativa labels did not form clearly distinct groups across the genome. Instead, the labels were associated with variation in a relatively small number of terpenes. Watts and colleagues, 2021.

The researchers also found that samples sharing a cultivar name could be as genetically and chemically different as samples with different names. That does not make every name meaningless. It does make a name alone a weak substitute for documented identity. The work was funded primarily by cannabis producer Bedrocan, and two authors were company employees—relevant context when assessing industry-connected research.

For readers exploring cannabis genetics, the distinction opens up more useful questions. Who documented the lineage? What evidence accompanies the description? Is a claim about ancestry, measured chemistry or someone’s interpretation of an experience?

Those are different kinds of information, even when they appear together in the same paragraph.

Building a Better Language for Cannabis Aroma

The next challenge is giving people a better vocabulary for what they actually smell.

In October 2025, a study published in PLOS One introduced an aroma lexicon containing 25 descriptive terms. A human panel evaluated 91 cannabis samples using that vocabulary. The aim was to make descriptions more consistent and allow meaningful comparisons between samples. Participants smelled the flower; they did not consume it as part of the assessment. Isaacson and colleagues, 2025.

The researchers found overlapping sensory characteristics between THC-dominant and CBD-dominant samples. They also found that terpene profiles alone predicted sensory character poorly. Even the measured sulfur compound profiles did not strongly predict perception. The lesson is subtle: identifying important molecules and predicting the complete human experience of a mixture are different scientific tasks.

A common vocabulary helps close that gap. If two people use “citrus” differently, their descriptions can sound precise while communicating different things. Reference standards give sensory researchers a way to make those words more comparable.

Reading Cannabis Descriptions with a Sharper Eye

Taken together, these studies suggest a more demanding approach to cannabis information. A responsible description should make clear what has been measured, what has been observed and what remains an interpretation. Readers should be able to distinguish a research finding from a colourful adjective without becoming chemists themselves.

Consider how differently a description reads when it separates its evidence. An ancestry statement can name the source of the lineage. A chemistry statement can identify the sample tested. An aroma description can acknowledge that it records a sensory impression. None needs to promise an identical result for every person.

This approach gives readers information they can examine, compare and question.

That also changes what makes an article or variety profile worth reading. A string of superlatives offers little to investigate. A documented lineage, an explanation of an unusual aroma or an honest account of uncertainty gives a reader something to understand and remember. Specific information invites curiosity in a way that another claim of exceptional strength cannot.

A Plant with More to Reveal

There is still plenty scientists have not resolved. The studies discussed here ask different questions, use different samples and measure different outcomes. An aroma experiment cannot establish medical benefits. A genetic analysis cannot predict an individual’s response. Bringing the findings together is useful precisely when those distinctions remain visible.

The emerging story is richer than a contest between percentages. Cannabis can be examined as a plant with ancestry, a complex chemical composition and a sensory identity that researchers are still learning to describe. Each perspective reveals something the others leave out.

For CSB readers, the invitation is to stay curious about those details. Follow the evidence behind familiar names. Ask what a number actually measures. Notice when a confident claim runs ahead of the research.

The most revealing cannabis stories begin where the label runs out of room.