By Dr. Allison Justice, Vice President of Cultivation at Outco
This presentation discusses:
Prized French wines are aged for years in oak barrels, as are famous whiskies. Tobacco is air-, fire-, flue- or sun-cured. Cannabis, however, is quickly dried and stored in a plastic bucket. Although many cannabis growers have proprietary ways of making flower flavorful and aromatic, little to no research is available for consistency.
Anecdotal examples show that chemical makeup is not only dictated by the strain/cultivar, but also influenced by grow methods, drying and curing. The lack of data prompted us to research what is happening during these processes. In this session, we will present our research at OutCo of how to affect and control the chemical makeup of flower; new protocols to monitor the dry and cure of cannabis flowers so we are able to modulate the terpene and cannabinoid profiles in our strain offering; and our latest findings in this exciting field of post-harvest cannabis research.
As the cannabis industry in the United States and throughout the world develops, the market is getting more competitive. Markets in a number of states are experiencing disruptions that will have lasting effects for cultivators, including oversupply and supply chain bottlenecks. Now more than ever, growers need to look for ways to differentiate their product or gain a bigger market share. Looking at yield efficiency, quality improvements and analyzing the cost of inputs versus value of the crop can help growers make the right choices in technology for lighting, irrigation and pest control among other technologies.
A series of free webinars in two weeks can help growers learn about some of the more advanced techniques in improving yield and quality. The Cannabis Cultivation Virtual Conference on May 23rd will explore a variety of tips and tricks for taking their cultivation operation to the next level. This event is free to attendees, made possible by sponsors VividGro and CannaGrow Expo.
Attendees will hear from experts in cannabis cultivation on a range of topics, including breeding, drying, curing, environmental monitoring and micropropagation. Adam Jacques, co-founder of Growers’ Guild Gardens and Sproutly, will discuss some of his experience with breeding high-CBD strains in Oregon. His talk will delve into some of the proper breeding procedures, along with how to hunt for particular phenotypes and developing specific cannabinoids and terpenes.
Dr. Allison Justice, vice president of cultivation at Outco, is going to present some of her findings in drying and curing at the company. She plans on sharing her research on how the post-harvest stages can affect and control the chemical makeup of flower. She’ll also discuss some new protocols to monitor the dry and cure of cannabis flowers so we are able to modulate the terpene and cannabinoid profiles.
Regardless of whether your grow is indoor or in a greenhouse, mold is a factor that all cultivators must consider.
After weeks of careful tending, pruning and watering to encourage a strong harvest, all cultivators are looking to sell their crop for the highest market value. A high mold presence, measured through a total yeast and mold count (TYMC), can cause a change of plans by decreasing crop value. But it doesn’t have to.
There are simple steps that any cultivator can take that will greatly eliminate the risk of mold in a grow. Below are some basic best practices to incorporate into your operation to reduce contaminants and mold growth:
Isolate dirty tasks. If you are cleaning pots, filling pots or scrubbing trimming scissors, keep these and other dirty tasks away from grow and process areas. Dirty tasks can contaminate the grow area and encourage mold growth. Set up a “dirty room” that does not share heating, ventilation and air conditioning with clean areas.
Compartmentalize the grow space. Mold can launch spores at speeds up to 55 miles per hour up to eight feet away without any air current. For this reason, if mold growth begins, it can become a huge problem very quickly. Isolate or remove a problem as soon as it is discovered- better to toss a plant than to risk your crop.
No drinks or food allowed. Any drinks or food, with the exception of water, are completely off limits in a grow space. If one of your employees drops a soda on the ground, the sugars in the soda provide food for mold and yeast to grow. You’d be surprised how much damage a capful of soda or the crust of a sandwich can do.
Empty all trash daily. Limiting contaminants in turn limits the potential for issues. This is an easy way to keep your grow clean and sterile.
Axe the brooms. While a broom may seem like the perfect way to clean the floor, it is one of the fastest ways to stir up dirt, dust, spores and contaminants, and spread them everywhere. Replace your brooms with hepa filter backpack vacuums, but be sure that they are always emptied outside at the end of the work day.
No standing water or high humidity. Mold needs water to grow, therefore standing water or high humidity levels gives mold the sustenance to sporulate. Pests also proliferate with water. Remove standing water and keep the humidity level as low as possible without detriment to your plants.
Require coveralls for all employees. Your employee may love his favorite jean jacket, but the odds are that it hasn’t been cleaned in months and is covered with mold spores. Clean clothing for your staff is a must. Provide coveralls that are washed at least once a week if not daily.
Keep things clean. A clean and organized grow area will have a huge impact on mold growth. Clean pots with oxidate, mop floors with oxidate every week, keep the areas in front of air returns clean and clutter-free, and clean floor drains regularly. The entire grow and everything in it should be scrubbed top to bottom after each harvest.
Keep it cool. Keep curing areas cool and storage areas cold where possible. The ideal temperature for a curing area is roughly 60 degrees and under 32 degrees for a storage area. Just like food, the lower the temperature, the better it keeps. High temperature increases all molecular and biological activity, which causes things to deteriorate faster than at cooler temperatures. However, curing temperature is a function of water activity more than anything.
Be Careful With Beneficials. Beneficial insects certainly have their place in the grow environment. However, if you have a problem with mold on only a small percentage of plants, any insect can act as a carrier for spores and exacerbate the problem. By the same token, pests spread mold more effectively than beneficials because they produce rapidly, where beneficials die if there aren’t pests for them to eat. It is best to use beneficials early in the cycle and only when necessary.
I have been studying microorganisms for over 35 years, and the elusive critters still fascinate me! Here in Microbiology 101, I write about the foundation of knowledge on which all microbiologists build. You may have a general interest in microbiology or have concerns in your operation. By understanding microbiology, you understand the diversity of microorganisms, their source, control of microorganisms and their importance.
The term microbiology covers every living being we cannot see with the naked eye. The smallest microbe is a virus. Next in size are the bacteria, then yeast and mold cells, and the largest microbes are the protozoans. The tiny structure of a virus may be important in the plant pathology of cannabis, but will not grow in concentrates or infused products. A virus is not living, until it storms the gate of a living cell and overtakes the functions within the cell. Viruses are the number one cause of foodborne illness, with the number one virus called Norovirus. Think stomach flu. Think illness on cruise ships. Viruses are a food service problem and can be prevented by requiring employees to report sickness, have good personal hygiene including good hand washing, and, as appropriate, wear gloves. Following Good Manufacturing Practices (GMPs) is critical in preventing the transfer of viruses to a product where the consumer can be infected.
The largest microbial cell is the protozoan. They are of concern in natural water sources, but like viruses, will not grow in cannabis products. Control water quality through GMPs, and you control protozoans. Viruses and protozoans will not be further discussed here. Bacteria, yeast and mold are the focus of further discussion. As a food microbiologist, my typical application of this information is in the manufacturing of food. Because Microbiology 101 is a general article on microbiology, you can apply the information to growing, harvesting, drying, manufacture of infused products and dispensing.
It is not possible to have sterile products. Even the canning process of high temperature for an extended time allows the survival of resistant bacterial spores. Astronauts take dehydrated food into space, and soldiers receive MREs; both still contain microbes. Sterility is never the goal. So, what is normal? Even with the highest standards, it is normal to have microbes in your products. Your goal is to eliminate illness-causing microorganisms, i.e. pathogens. Along the way, you will decrease spoilage microbes too, making a product with higher quality.
Yeast and mold were discussed on CIJ in a previous article, Total Yeast & Mold Count: What Cultivators & Business Owners Need to Know. Fuzzy mold seen on the top of food left in the refrigerator too long is a quality issue, not a safety issue. Mold growth is a problem on damaged cannabis plants or cuttings and may produce mycotoxin, a toxic chemical hazard. Following Good Agricultural Practices (GAPs) will control mold growth. Once the plant is properly dried, mold will not grow and produce toxin. Proper growing, handling and drying prevents mycotoxins. Like mold, growth of yeast is a quality issue, not a safety issue. As yeast grow, they produce acid, alcohol and carbon dioxide gas. While these fermentation products are unwanted, they are not injurious. I am aware that some states require cannabis-infused products to be alcohol-free, but that is not a safety issue discussed here.
What are the sources of microorganisms?
People. Employees who harvest cannabis may transfer microorganisms to the plant. Later, employees may be the source of microbes at the steps of trimming, drying, transfer or portioning, extract processing, infused product manufacture and packaging.
Ingredients, Supplies and Materials. Anything you purchase may be a source of microorganisms. Procure quality merchandise. Remember the saying, “you get what you pay for.”
Environment. Starting with the outdoors, microbes come from wind, soil, pests, bird droppings and water. When plants are harvested outdoors or indoors, microbes come from the tools and bins. Maintain clean growing and harvesting tools in good working condition to minimize contamination with microbes. For any processing, microbes come from air currents, use of water, and all surfaces in the processing environment from dripping overhead pipes to floor drains and everything in between.
In Part 2 I will continue to discuss the diversity of microorganisms, and future articles will cover Hazard Analysis and Critical Control Points (HACCP) and food safety in more detail. What concerns do you have at each step of operations? Are you confident in your employees and their handling of the product? As each state works to ensure public health, cannabis-infused products will receive the same, if not more, scrutiny as non-cannabis food and beverages. With an understanding and control of pathogens, you can focus on providing your customers with your highest quality product.
Hazard analysis and critical control points (HACCP) is a robust management system that identifies and addresses any risk to safety throughout production. Originally designed for food safety through the entire supply chain, the risk assessment scheme can ensure extra steps are taken to prevent contamination.
The FDA as well as the Food Safety and Inspection Service currently require HACCP plans in a variety of food markets, including high-risk foods like poultry that are particularly susceptible to pathogenic contamination. As California and other states develop and implement regulations with rigorous safety requirements, cannabis cultivators, extractors and infused product manufacturers can look to HACCP for guidance on bolstering their quality controls. Wikipedia actually has a very helpful summary of the terms referenced and discussed here.
The HACCP system consists of six steps, the first of which being a hazard analysis. For Dr. Markus Roggen, vice president of extraction at Outco, a medical cannabis producer in Southern California, one of their hazard analyses takes place at the drying and curing stage. “When we get our flower from harvest, we have to think about the drying and curing process, where mold and bacteria can spoil our harvest,” says Dr. Roggen. “That is the hazard we have to deal with.” So for Dr. Roggen and his team, the hazard they identified is the potential for mold and bacteria growth during the drying and curing process.
The next step in the HACCP system is to identify a critical control point. “Correct drying of the flower will prevent any contamination from mold or bacteria, which is a control point identified,” says Dr. Roggen. “We also have to prevent contamination from the staff; it has to be the correct environment for the process.” That might include things like wearing gloves, protective clothing and hand washing. Once a control point is identified, the third step in the process is to develop a critical limit for those control points.
A critical limit for any given control point could be a maximum or minimum threshold before contamination is possible, reducing the hazard’s risk. “When we establish the critical limit, we know that water activity below 0.65 will prevent any mold growth so that is our critical limit, we have to reach that number,” says Dr. Roggen. The fourth step is monitoring critical control points. For food manufacturers and processors, they are required to identify how they monitor those control points in a written HACCP plan. For Dr. Roggen’s team, this means using a water activity meter. “If we establish the critical control point monitoring, water activity is taken throughout the drying process, as well as before and after the cure,” says Dr. Roggen. “As long as we get to that number quickly and stay below that number, we can control that point and prevent mold and bacteria growth.”
When monitoring is established and if the critical limit is ever exceeded, there needs to be a corrective action, which is the fifth step in a HACCP plan. In Dr. Roggen’s case, that would mean they need a corrective action ready for when water activity goes above 0.65. “If we don’t have the right water activity, we just continue drying, so this example is pretty simple,” says Dr. Roggen. “Normal harvest is 7 days drying, if it is not dry enough, we take longer to prevent mold or bacteria growth.”
The sixth step is establishing procedures to ensure the whole system works. In food safety, this often means requiring process validation. “We have to double check that our procedure and protocols work,” says Dr. Roggen. “Checking for water activity is only a passive way of testing it, so we send our material to an outside testing lab to check for mold or bacteria so that if our protocols don’t work, we can catch those problems in the data and correct them.” They introduced weekly meetings where the extraction and cultivation teams get together to discuss the processes. Dr. Roggen says those meetings have been one of the most effective tools in the entire system.
The final step in the process is to keep records. This can be as simple as keeping a written HACCP plan on hand, but should include keeping data logs and documenting procedures throughout production. For Dr. Roggen’s team, they log drying times, product weight and lab tests for every batch. Using all of those steps, Dr. Roggen and his team might continue to update their HACCP plans when they encounter a newly identified hazard. While this example is simplistic, the conceptual framework of a HACCP plan can help detect and solve much more complex problems. For another example, Dr. Roggen takes us into his extraction process.
Dr. Roggen’s team, on the extraction side of the business, uses a HACCP plan not just for preventing contamination, but for protecting worker safety as well. “We are always thinking about making the best product, but I have to look out for my team,” says Dr. Roggen. “The health risk to staff in extraction processes is absolutely a hazard.” They use carbon dioxide to extract oil, which carries a good deal of risks as well. “So when we look at our critical control points we need to regularly maintain and clean the extractor and we schedule for that,” says Dr. Roggen.
“My team needs respirators, protective clothing, eyewear and gloves to prevent contamination of material, but also to protect the worker from solvents, machine oil and CO2 in the room.” That health risk means they try and stay under legal limits set by the government, which is a critical limit of 3,000 ppm of carbon dioxide in the environment. “We monitor the CO2 levels with our instruments and that is particularly important whenever the extractor is opened.” Other than when it is being opened, Dr. Roggen, notes, the extractor stays locked, which is an important worker safety protocol.
The obvious corrective action for them is to have workers leave the room whenever carbon dioxide levels exceed that critical limit. “We just wait until the levels are back to normal and then continue operation,” says Dr. Roggen. “We updated our ventilation system, but if it still happens they leave the room.” They utilize a sort of double check here- the buddy system. “I took these rules from the chemistry lab; we always have two operators working on the machine on the same time, never anyone working alone.” That buddy check also requires they check each other for protective gear. “Just like in rock climbing or mountain biking, it is important to make sure your partner is safe.” He says they don’t keep records for employees wearing protective gear, but they do have an incident report system. “If any sort of incident takes place, we look at what happened, how could we have prevented it and what we could change,” says Dr. Roggen.
He says they have been utilizing some of these principles for a while; it just wasn’t until recently that they started thinking in terms of the HACCP conceptual framework. While some of those steps in the process seem obvious, and it is very likely that many cannabis processors already utilize them in their standard operating procedures and quality controls, utilizing the HACCP scheme can help provide structure and additional safeguards in production.
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