Microbial Growth in Packaged Cannabis Products
Occasionally, regulators may come across contaminated products like flower and pre-rolls on the shelves, despite these lots having previously met state standards. Often, this anomaly can be traced back to post-harvest environmental control.
The key metric here is water activity, a measurement that indicates the likelihood of continuous microbial growth, even in a packaged state. For example, let's consider a plant material that passes the 10,000-count-limit test with a count of 7,000. If the water activity is out of spec, this count could double over a few weeks, resulting in non-compliant material. To prevent such microbial growth post-packaging, 11 of 29 states now mandate the testing of water activity, and we foresee other states soon following suit.
In California, the upper water activity limit for flower is established at 0.65. If flower material is not cured to a water activity measure of at least 0.70, it can promote the growth of yeast and mold. With strict water activity limits set for packaged cannabis, the scenario of microbial contamination, such as the recent incidents in Denver, can be prevented.
But how do you maintain a desirable water activity of ≤0.65 post-harvest? It requires dedication, team cooperation, and rigorous standard operating procedures (SOPs). All post-harvest processes should ideally be performed in a controlled environment where the relative humidity (RH) is kept between 55– 65%. Achieving a stable humidity (equilibrium relative humidity, ERH) across all post-harvest processes is crucial.
To accomplish ERH, monitoring and controlling potential humidity effects due to weather, temperature, and personnel traffic in your processing rooms are necessary. Well-implemented practices, solidified in your SOP, ensure you're taking every step to maintain the required water activity, thereby eliminating microbial growth in the packaged products.
bIn the packaging phase, microenvironment control can be achieved using relative humidity control packets like Boveda and Integra brands, which are designed to maintain an internal package humidity of 62%. These packets absorb and release water based on relative humidity, mitigating temperature fluctuations and maintaining a microbiologically stable cannabis product with an extended shelf life and a yeast and mold count compliant with state-mandated tests.
In Random Mold Tests at 25 Denver Dispensaries, 80 Percent Fail
These products were not contaminated at the time of delivery from the supplier, as evidenced by METRC documentation. The origin of this contamination is likely because of conditions within the sealed packages that were favorable to microbial growth.
When you consider the large-scale environmental conditions in which the cannabis is grown, harvested, dried, cured, and stored and compare it to the internal microenvironment of the packaging, it makes sense that similar environmental conditions would affect the packaged products in the same way. Just as we have seen that controlled environment agriculture (CEA) is necessary for successful indoor cultivation, we find that a form of CEA is necessary for the microenvironment inside the packaging of the harvested cannabis.
When evaluating microbiological contamination risks, you must consider both the large-scale and the microenvironments of the products across the entire supply chain from grower to consumer.
Links to Articles:
https://www.cannabisbusinesstimes.com/news/denver-dispensaries-testing-failures-yeast-mold-retail
Understanding Microbial Contamination in Cannabis: Protect Your Business and Ensure Quality
Post-Harvest Testing - After the curing process and before packaging, your cannabis products undergo stringent testing. At this stage, microbial contamination can turn your promising harvest into a potential business risk.
Post-Packaging Testing - Even after successful post-harvest testing, products can fail microbial contamination test after packaging. This unexpected setback can significantly impact your product line and business. Statistically speaking, around 10% of cannabis fails the microbial contamination test at the cultivation facility post-harvest. This seemingly small percentage can be the stark difference between business success and failure, and could mean the world to your bottom line.
Turning Challenges into Opportunities with Informed Decisions
Familiarizing yourself with these critical points in the supply chain and knowing how to navigate them effectively is integral to running a successful cannabis business. Equipped with this knowledge, you can anticipate potential threats, make informed decisions, and keep your business robust and thriving. Join the vanguard of responsible and successful cannabis businesses by ensuring the safety and quality of your products. By minimizing microbial contamination, you can maximize profits and uphold your brand's reputation. Don't let that critical 10% dictate your success - take control and stay ahead in the ever-evolving cannabis industry.