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In the cannabis and hemp industries, determining and obtaining the optimal particle size is crucial for maximizing the efficiency and quality of your pre-roll production and extraction processes. Cultivators and processors often face challenges in achieving the desired consistency and potency in their final products due to inconsistently milled material.
As with any product, the quality is largely determined by the starting materials and processing methods. You can grow the best flower on the planet, but if you’re not processing it correctly, the consumer experience can be negatively impacted. For example, pre-rolls that are packed inconsistently or incorrectly will not produce the ideal smoke, and extract products that are manufactured using inferior equipment or starting material that’s incorrectly prepared will not result in the highest quality end product.
The potency of the flower and preservation of cannabinoids is directly related to how the material was prepared and processed through the manufacturing steps. Ultimately, this directly impacts the quality of the end product that the consumer is purchasing and the profit potential associated with that product.
Types of Mills and Their Functionality
In order to obtain precisely milled material for processing, processors will employ an industrial cannabis grinder, or mill, to break up the cannabis buds. Each type of mill functions differently to achieve the desired particle size. Common types include blade mills, hammer mills, and burr mills, and the machine is essentially either cutting, squeezing, or breaking up the cannabis material.
● Hammer Mills: A rotating shaft pushes the cannabis material against a screen to break up the buds into smaller pieces. These mills may have various screen options to create the desired grind size.
● Blade Mills: These mills use sharp rotating blades to cut the cannabis material into smaller pieces.
● Burr Grinders: These mills use two abrasive surfaces to grind the material. The distance between the burrs can be adjusted to control the size of the grind.
While reducing the particle size, producers want to ensure their material stays as potent and pure as possible. Some cultivators may be concerned that milling may influence the cannabinoid recovery and the resulting final THC levels. Studies have shown that with the proper milling conditions and technique, the flower quality is not degraded during the grinding process, and the ratio of THCA to THC is not affected. Not only is quality preserved through milling, but the smaller particle sizes actually allow for better extraction selectivity and higher recoveries of terpenes and cannabinoids.
Depending on the intended end product and processing method, your choice of a mill will affect how the material gets to the desired particle size. Producers will notice a difference in the material between using a perforated screen-style mill versus a bladed mill that shreds the flower as it relates to the smokeability of the product.
Some of the biggest factors to consider with the type of cannabis mill include the mill size and capacity, the machine’s material and construction, the grinding mechanism, throughput performance and processing efficiency, the machine’s adherence to regulations and laws surrounding cannabis equipment, and the features of the mill (option of particle size output, cleanability, serviceability, etc.).
The Challenges With Material Preparation
When cannabis material is improperly milled prior to pre-roll production or extraction processes, it poses numerous issues for the quality of the product and the processing efficiency of the facility.
● Inconsistent THC and CBD Delivery: The particle size of the cannabis material affects the delivery of cannabinoids when inhaled or smoked. For joints and pre-rolls, a larger particle size tends to result in longer-lasting effects but may deliver cannabinoids less efficiently per puff. Conversely, smaller particles deliver more cannabinoids quickly but may not sustain the desired effects over time.
● Extraction Efficiency: The grind size significantly influences the efficiency of extraction processes. In solvent-based extractions (e.g., using hydrocarbons or alcohol), finer particles can lead to channeling, where the solvent bypasses some material, reducing extraction efficiency. On the other hand, too coarse particles can result in incomplete extraction, leaving valuable material on the table and compromising profit potential.
● Product Consistency: Variations in particle size can lead to inconsistent product quality. This inconsistency affects the reproducibility of pre-rolls and extracted products, making it challenging to maintain a stable product line.
Determining and Obtaining Optimal Particle Size
Once you have determined the best machine for your needs, you’ll want to figure out what particle size you should grind to for the best product quality and optimal processing efficiency. The key in milling is to create a homogenous starting material and obtain a specific, consistent particle size. Getting consistently milled feedstock also eliminates bottlenecks in processing caused by delays from material sourcing. Having high-quality milled cannabis can save thousands of dollars by reducing operation cycle times and increasing equipment uptime.
This allows the producer to control the exact output of their material for extraction processing and proper joint architecture. As a result, cultivators see bigger returns on their investment by delivering consistent products on a consistent schedule.
Pre-Roll Production
Milling for extraction processes versus milling for pre-roll production will require different particle sizes and grinding styles. For joints and pre-rolls, studies show that creating specific blends of different particle sizes is best for joint architecture, which includes factors like smokability, cannabinoid delivery, and reproducibility. With milling to particular particle sizes for pre-rolls, producers can create products specific to their purchaser’s requests and current market demands.
Additionally, with a better understanding of joint architecture and cannabinoid delivery, pre-roll manufacturers can deliver more accurate THC and CBD levels within their products, and consumers are more informed about the amounts of each cannabinoid being consumed while smoking.
Extraction Processing
An effective grinding process before extraction helps to preserve potency, while reducing the presence of undesirable residue in your extract, such as plant waxes and chlorophyll. With extraction processes, the grind size will depend on the type of extraction being done.
Your processing will also be informed and influenced by the specific cultivar being produced, whether that is cannabis or hemp flower. With hemp processing, the end product goal is typically isolate, achieving as close to 100% purity as possible. In cannabis processing, the end goal with extraction is more connoisseur products like live rosin, diamonds, shatter, and crumble.
Solvent-based extraction processes can be achieved using a different grind size depending on the solvent used. Processing flower for solventless rosin pressing or bubble hash washing will also require their own unique processes.
Milling for Processing: Specific Particle Size for Maximizing Quality and Yield
To address these challenges in processing, cultivators and processors can implement precise milling techniques to achieve the optimal particle size for their specific needs. Regardless of the grind size required for your specific type of extraction or pre-roll production, you’ll want a precise milling method to preserve potency. Look to maintain an ultra-low-speed milling process with a lower-impact motor that protects the integrity of trichomes and minimizes losses caused by heat degradation. In contrast to high-speed milling methods, the Mobius Mills produce minimal friction and heat, so your flower retains more THC and terpenes for higher-quality results.
Pre-Roll Production:
● Target Particle Size: For pre-rolls, a particle size of around one millimeter is ideal for quick and efficient THC delivery. This size allows for more THC to be released per puff, providing a potent experience. For a longer-lasting experience, a particle size of three to five millimeters can be used, which burns slower and delivers cannabinoids over an extended period. Producers can also make custom blends of grind sizes including a mixture of one-millimeter and three- to five-millimeter particle sizes for a well-constructed joint that burns evenly and has consistent cannabinoid delivery.
● Milling Techniques: Using industrial grinders that can precisely control the particle size ensures uniformity in pre-rolls. This uniformity enhances the smoking experience by providing consistent burn rates and cannabinoid delivery.
Solvent-Based Extraction:
● Optimal Grind Size: In hydrocarbon extraction, slightly coarser particles (around two to three millimeters) prevent channeling and allow the solvent to interact more thoroughly with the material. For the ethanol extraction, you’re working with a more abrasive solvent as compared to the hydrocarbon extraction, so a finer grind can be used (but not too fine). CO2 extraction will require the finest grind of all the solvent-based extraction methods.
● Column Packing: Properly packing the extraction column with the milled material is crucial. Uniform packing prevents channeling and ensures the solvent flows evenly through the material, maximizing extraction efficiency.
Solventless Extraction:
● Rosin Pressing: For solventless extraction methods like rosin pressing, the particle size should be optimized to balance yield and quality. Finer particles increase surface area, enhancing cannabinoid release, but can also result in unwanted plant material in the final product. A medium grind (around two to three millimeters) is often preferred. You’ll also want to start with a uniform “puck” of flower that has been compacted together using something like a pre-press mold.
Maintaining Potency Through Processing
Achieving the optimal particle size through precise milling is essential for improving the quality and consistency of cannabis pre-rolls and extraction products. By understanding the impact of particle size on cannabinoid delivery and extraction efficiency, processors can tailor their milling techniques to meet specific product goals.
This approach not only enhances the consumer experience but also ensures that products meet regulatory standards and market demands while allowing for maximum returns and profit potential for the producer.
By focusing on consistent particle size, cultivators and processors can overcome many of the challenges associated with cannabis and hemp product preparation, leading to better outcomes and more satisfied consumers.
