Results from Phase I of the groundbreaking “Science of Smokeability” study are in, and for the first time, researchers have scientific data showing exactly how water activity and moisture levels affect what consumers actually experience when smoking a pre-roll.
According to the results, gathered from both laboratory experiments and from surveys of actual pre-roll smokers, pre-rolls with a water activity of 0.65 aW deliver significantly more cannabinoids and terpenes to consumers than products at other moisture levels, all with less harshness.
With this knowledge, pre-roll producers can, for the first time, begin optimizing pre-roll quality based on actual smoking performance rather than guesswork.
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What is the Science of Smokeability?
The “Science of Smokeability” is a first-of-its-kind scientific assessment that goes beyond traditional laboratory testing led by Dr. Allison Justice and Dr. Markus Roggen, both leading scientists in the cannabis industry. This research is a multi-year project that combines rigorous laboratory analysis with real-world consumer experience.
The researchers used a sophisticated approach that paired smoking machine analysis with actual consumer testing. First, high-quality hemp pre-rolls from a strain called “FunDip” were carefully manufactured on professional pre-roll equipment and then stabilized at three different water activity levels: 0.45 aW, 0.65 aW, and 0.85 aW.
Using a machine that literally smokes a real joint, scientists measured exactly what compounds were delivered in the smoke. Meanwhile, consumers received pre-rolls in airtight containers and provided feedback on their smoking experience, creating a comprehensive picture of how water activity affects product performance.
A quick note, though: consumers were only sent 0.45 and 0.65 aW pre-rolls, as 0.85 aW is outside of the safety range because it can support microbial growth.
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Pre roll study results revealed
Phase I results from the study were published in the March/April 2025 issue of Cannabis Science and Technology.
The 0.65 aW level emerged as the clear winner across multiple measures, delivering superior performance that could translate directly into better customer satisfaction and potentially higher sales for producers.
When researchers analyzed the smoke from pre-rolls at different water activity levels, they found that those at 0.65 aW delivered the highest cannabinoid concentration, with 0.45 aW pre-rolls following closely behind. The study tested for multiple cannabinoids, including CBD, CBG, CBC, and THC, with consistent results across all compounds tested.
The difference was dramatic for the wettest samples: pre-rolls at 0.85 aW produced only 30 percent of the cannabinoid content compared to the optimal 0.65 aW level.
This finding has significant implications because it means consumers smoking pre-rolls with the wrong moisture level are literally getting fewer active compounds for their money, and may turn to other brands to provide them.
The terpene results told an equally compelling story. Pre-rolls at 0.65 aW consistently delivered the highest terpene concentrations overall, leading researchers to conclude that this level would provide “the most pronounced flavor profile due to their greater terpene yield.”
Perhaps most importantly for consumer satisfaction, the consumer survey revealed significant differences in the harshness of each smoke. While overall desirability slightly favored the 0.65 aW pre-rolls, the 0.45 aW pre-rolls produced “a more irritating experience” for smokers, presumably creating a harsher smoke due to the drier cannabis.
That could make a smoother experience at 0.65 aW a key differentiator for customer retention.
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Why does this science matter?
Beyond product quality, the study highlights potential financial implications for producers.
The difference between flower at 0.45 aW versus 0.65 aW water activity corresponds to moisture content levels of about five percent and nine percent, respectively. According to the researchers, this difference amounts to about 18.14 grams per pound of flower.
At an assumed market price of, say, $1.50 per gram, this weight differential represents an estimated revenue loss of $27.20 per pound for material at the lower water activity level, or about four percent of total revenue per pound.
The results provide pre-roll manufacturers with concrete, science-based guidance for optimizing their products.
Targeting a water activity of 0.65 aW could help pre-roll manufacturers maximize cannabinoid delivery to consumers, enhance flavor profiles through optimal terpene preservation, reduce harshness for a smoother smoking experience, and potentially increase revenue through optimal moisture retention.
For producers currently working with different moisture levels, these findings suggest that adjusting water activity could be a relatively straightforward way to improve product performance without major changes to cultivation or processing methods. The research highlights the critical importance of proper drying and curing techniques, as these processes directly influence the final water activity of cannabis products.
For an industry and a category where customer satisfaction and repeat business are paramount, achieving that 0.65 aW sweet spot could be the difference between a pre-roll that keeps them coming back and one that doesn’t.