The Art of the Pre-Roll

The cannabis industry is undergoing a seismic shift, with pre-rolls officially dethroning flower as the top-selling segment in the market. But producing a perfect, premium pre-roll is an art and a science. For example, to ensure a smooth, even burn, manufacturers must carefully control the flower’s particle size as well as maintain an optimal moisture content to safeguard the delicate terpenes. As demand soars, producers are increasingly turning to automation for the high throughput and consistency that manual methods can’t match, shifting their focus from product weight to volume. However, the quest for full automation is not without its own challenges.

The Quality Crisis and the Call for Consistency

In the early years of the cannabis industry boom, pre-rolls were not a very popular option. Flower has been dominating the market for quite some time, but that is changing. In 2025, Headset data reported that in Canada, cannabis pre-rolls have surpassed flower as the number one best-selling product segment (1). Pre-roll sales are anticipated to break last year’s record and have acquired $982 million in sales so far this year, as well as hold 34% of market share. Cannabis flower has reached $909.4 million with a 32% market share and has seen a -2.5% decline from 2024.

When pre-rolls first came on the market, they were a product for manufacturers to off load low quality materials. Farmers would fill the pre-rolls with shake and trim, such as sticks and stems, which are not high-quality materials.

As the industry has evolved, consumer preferences have changed and they are more interested in receiving a recreational cannabis experience as most consumers and sales are in the recreational category. That is why we see flower, pre-rolls, and vapes dominating, whereas tinctures, topicals, etc., are not nearly as popular, explained Harrison Bard, Co-founder and CEO of Custom Cones USA and DaySavers.

Inside the pre-roll category, infused pre-rolls are driving revenue growth (1). These types of products tend to hold a higher price point due to the inclusion of a concentrate. With infused pre-rolls, potency is considered a top factor of product quality. With their increased amounts of tetrahydrocannabinol (THC) and stronger flavor profiles, they may one day outpace the single-strain hybrid, but for now, single strains are the most popular option.

“You’re starting to see some infused with different cannabinoids, the alternative ones, like CBC, CBG, CBN, but more often than not, they’re just infused with more,” said Bard. “It’s not just about THC percentage, but that’s what consumers want. They want the most bang for their buck, so they go for potency. Most infused pre-rolls just have more THC, and they’re most likely getting infused with distillate. That’s really popular because it’s super potent, like 90 plus percent THC. It’s easy to work with.”

A major issue being witnessed in the cannabis industry is lab shopping. Technology Networks Applied Sciences (2) defines lab shopping as “the practice of offering (shopping) a cannabis product to different testing labs and then ultimately partnering with the lab that offers the most favorable test results.” In this scenario, favorable test results mean higher levels of THC and other cannabinoids or terpenes, and because consumers are interested in high-THC products, that means manufacturers can charge more for higher THC products.

The legal cannabis space needs consistency and regulation. Through these misleading practices, fraudulent products are hitting the shelves for consumers to purchase and leaving honest manufacturers and laboratories with no consumers and safe products with proper labeling in stores.

Engineering the Input—The Science of Particle and Moisture and the Art of the Grind

There are various factors that determine the quality of a pre-roll. For example, once the strain of flower has been chosen, you need to grind it down. Here, particle size is very important as it impacts the quality of the burn.

Particle Size

“We usually recommend particle size between three and four millimeters, and then you always have a little bit of smaller particle in there that kind of fills in the gaps,” said Kyle Loucks, CEO and Founder of RollPros. He went on to explain how having too coarse of a grind can harm the burn of the joint.

“You can get little pockets of air in there. So that’s really what would start a canoeing event. It’ll cause the joint to burn quicker,” Loucks stated. “One of the things that I saw with a cone is, if you’re filling it from the top, and you have a bigger chunk go in, there’s going to be a void behind it. And so, the air flows through the path of least resistance, and it’s going to hit that pocket. Once it hits that pocket, it’s going to burn your paper, and then all sudden, you’re experiencing canoeing issues that are prevalent in the cones which is caused purely from how they’re being made.”

Moisture Content

Aside from selecting the proper particle size for your roll, figuring out the ideal moisture content for cannabis flower is also important because too little or too much moisture can cause the flower to become too dusty or clump during the grinding process.

“Moisture content is super important. After you spend all that time growing the cannabis, it all comes down to the cure,” explained Bard. “You could easily ruin a whole crop of cannabis if you get the cure wrong. And once you are drying out the cannabis, it is reversible in the sense that you could re-moisturize it, you could get it to be more humid again or have more moisture content, but once you cure it and those terpenes are gone, the terpenes will never come back.”

In pre-roll manufacturing, Bard mentioned that the ideal moisture content should be between eight to 14%. On top of moisture content, it’s important to look at water activity. A recent peer-reviewed study (3) titled, “Impact of Water Activity on the Chemical Composition and Smoking Quality of Cannabis Flower: The Science of Smokability Phase I Results,” defined water activity (aW) as the “availability of free water in a product and differs from total moisture content by directly influencing microbial growth, chemical stability, and combustion behavior.” Water activity can be a contributing factor to the performance of the product, combustion behavior, and consumer satisfaction. It can affect the quality of cannabis while it is stored, during packaging, and even with consumption. The authors expressed how, “It is standard practice in the cannabis industry to dry and cure to water activity levels around 0.65 aW to avoid microbial growth and contamination.” The researchers studied levels below 0.85 aW and above 0.45 aW to better understand the role of water activity when evaluating smokeability.

The authors concluded that, “By optimizing water activity levels, it may be possible to enhance the delivery of desirable compounds, such as cannabinoids and terpenes, while minimizing the presence of potentially harmful elements. Additionally, consumers could not tell the difference between pre-rolls prepared at 0.45 aW and 0.65 aW suggesting lower water activity may be safer for shelf life and avoiding microbial growth,” (3).

Manual vs. Pre Roll Automation

What separates manual and automated pre-roll manufacturing is consistency. Automated machines can deliver a more consistent product. Machines, such as RollPros’ Blackbird, allow for customization such as adjusting how tightly the joint is rolled via a touchscreen panel. Blackbird utilizes the company’s patented TruRoll technology which mimics a joint being rolled by hand but maintains precision and consistency with a machine. By adjusting the tightness of the roll, “you can change the draw of the joint,” said Loucks. “Every single joint that ends up in your customer’s hands is going to be a good smoking joint.”

A major challenge in automating the pre-roll process is the perceived compromise between quality and throughput. As Loucks explained, many high-volume machines require manufacturers to compromise product integrity—by over-drying the flower or adding low-grade trim—simply to maintain operational speed. While this maximizes joint count, it ultimately destroys the consumer experience. “When designing these machines, I really held to my standards that it has to run fresh, sticky flower at scale,” Loucks stated. He concluded that the ability to achieve both high quality and high production volume simultaneously is the key differentiator that sets next-generation automation apart in the market.

Custom Cones USA offers a product portfolio which includes pre-roll filling machines called King Kone and Fill N Fold. These machines are able to produce a volume output of around 1,000 pre-rolls or more per hour. The challenges in high-volume pre-roll manufacturing extend beyond grinding, centering on the flawed metrics of weight and potency, explained Bard. For novice companies, pre-roll weight is a fixation, but seasoned manufacturers recognize its arbitrariness. Since moisture escapes over time, a pre-roll weighing a perfect gram today will inevitably be lighter weeks or months later, especially after sitting on shelves. This problem is compounded by current THC testing protocols, where a small sample’s percentage is extrapolated to an entire lot of thousands of grams. This sampling issue, combined with the prevalent practice of manufacturers submitting only the most potent material (often coupled with inflated lab results), creates systemic inconsistency and compromises consumer trust.

To overcome the variability of cannabis material, the focus has shifted from weight to volume. A significant technical hurdle lies in the metering tray process, which dispenses the flower into the cones. Because every strain has a different density and moisture level that changes over time, a fixed metering tray is inefficient. Constant innovation is therefore necessary to help manufacturers dial in the exact material volume needed. For instance, adjustable metering trays that allow for the stacking of different shims and thicknesses offer a practical solution, enabling manufacturers to compensate for these strain and environmental changes quickly, said Bard.

“The biggest challenge that we’re seeing with pre-roll manufacturers is closing the pre-rolls. It’s pretty easy to fill the pre-rolls. You put the flower into the metering tray or right into the top of the machine, and it fills around 100 or more pre-rolls in one go. But then the most annoying part for manufacturers, is taking each pre-roll out, one at a time, and closing them. While machines can easily fill a hundred cones in one go, manually taking out, and closing each joint is labor-intensive and slow,” Bard commented.

Machines such as King Kone and Fill N Fold automate the process of tamping and closing, significantly streamlining the final step to produce a consistent and finished product.

Automation does come with challenges. It can lead to businesses maintaining less staff which can lower costs, but this can also make the company more prone to staff shortages, impacting production. If a staff worker is sick, a business may not be able to maintain their production line if enough staff isn’t trained and available to take over. With a properly staffed and educated team, each member can properly handle the input and output from the machine.

Despite the ease of using a machine, it is still best for them to be monitored by staff. Through observation, employees are able to ensure the consistency of each pre-roll coming out of the machine, and if an issue arises, adjustments can be made to continue providing a quality product.

Conclusion

The mandate for achieving a premium smoking experience begins not with the machine, but with the flower itself. Critical factors like precise particle size and optimal moisture content must be controlled before rolling to ensure the preservation of delicate terpenes and natural resins. To protect these attributes, automated solutions have moved beyond outdated cone-stuffing techniques, which often damaged flower and created structural flaws.

References

1. Seven key insights into Canada’s Pre-Roll Market. Grow up conference and expo: Presented by Quality Horticulture https://growupconference.com/grow-up-news/seven-key-insights-into-canadas-pre-roll-market/. (accessed Oct 13, 2025).
2. Bear-McGuinness, L. What is lab shopping and how can the cannabis industry tackle it? Technology Networks. March 6, 2023. https://www.technologynetworks.com/applied-sciences/articles/what-is-lab-shopping-and-how-can-the-cannabis-industry-tackle-it-390058 (accessed Oct 14, 2025).
3. Justice, A.; Kirk, R.; Manning, A.; Roggen, M.; Shields, M. Impact of Water Activity on the Chemical Composition and Smoking Quality of Cannabis Flower: The Science of Smokability Phase I Results, Cannabis Science and Technology, 2025, 8(2), 10-19.

About the Author

Madeline Colli is the Editor for Cannabis Science and Technology magazine. Direct correspondence to: MColli@mjhlifesciences.com.

How to Cite This Article

Colli, C. The Art of the Pre-Roll, Cannabis Science and Technology, 8(5), 19-22.