Cannabis extraction and refinement create different raw materials for formulation. They are critical processes that separate cannabis extracts into their component molecules. Cannabinoid distillation is a particularly complex stage of the extraction and refinement process that involves a nuanced interplay among component boiling points, heat and vacuum.

Here are some tips and tricks producers can use in their distillation protocols to optimize their results.

1. Aim for highly refined and clean material.

Limit the number of substances that interact during the distillation process and components that can negatively affect the performance of the equipment. For example, certain fatty acids have boiling points near cannabinoids and will often polymerize, which diminishes product purity and increases system maintenance. Also, components of the refinement process (i.e., clarifying agents) can cause isomerization during distillation. To mitigate this, refine extracts prior to distillation. Refinement processes include winterization, clarification and scrubbing filtration.

2. Fully decarboxylate and degas the material.

A simple way to increase the throughput of the distillation process is to decarboxylate and degas the cannabis extract before distillation. Decarboxylation and degassing are the processes of converting the acid form cannabinoids to the neutral forms and removing volatiles, respectively, by applying heat and agitation. By undertaking those two processes, the vacuum operates under reduced load and more cannabinoids are distilled per unit time.

3. Use a well-designed vacuum system.

The atmospheric boiling points of cannabinoids are not known to any degree of certainty because these heavy molecules tend to degrade before they boil. However, by removing atmosphere, the cannabinoids can be encouraged to boil at a lower temperature. Their boiling points under vacuum (i.e., 5x10-3 Torr)—as documented by Adams et al. in 1941 and Gaoni & Mechoulam in 1964—are between 155 and 160 degrees Celsius. That’s why it’s important to have a substantial vacuum system to reduce the heat required to vaporize cannabinoids and minimize the risk of degradation. An ideal vacuum system for this application is a dual-stage rotary-vane pump designed to pull to 1x10-4 Torr with a diffusion pump to increase the depth and stability of the vacuum under load. It’s also important to correctly size the tubing and seal the connectors.

4. Maintain short heated-surface contact.

Heat can degrade or isomerize cannabinoids. Use a system that can deliver heat to a thin layer of oil to minimize total heat exposure. Wiped film or centrifugal systems are ideal for this because the oil’s contact with heat is several seconds compared to several hours. Finally, stainless steel heating surfaces (i.e., still body or centrifugal plate) increase the efficiency of heat transfer and the throughput of the distillation process.

Mark June-Wells, Ph.D., is the principal owner, and Brandon Webster is a process consultant with Sativum Consulting Group, a company that helps clients reduce lag time between laboratory set-up and revenue generation.

Foliar tissue analysis is an extremely useful tool for growers managing plant nutrition of cannabis. It falls into two major categories: routine analysis and diagnostic analysis. Routine analysis is for problem prevention, whereas diagnostic analysis is for problem solving.

The routine analysis allows growers to monitor nutrient uptake in the plant during production. This requires a grower to take multiple samples over the entire course of the growing season to identify problems or issues before they become serious concerns.

Growers can use diagnostic analysis to diagnose deficient or toxic nutrients when the plants are displaying negative symptoms. This process helps identify the specific problem and is primarily a corrective tool. Plant tissue analysis is especially useful in determining micronutrient levels in the plant and has a greater level of accuracy than a substrate test using a water-based extraction.

Tissue Analysis Strategies for Cannabis Growers

Routine analysis sampling is a general management tool when the plant is displaying no negative symptoms. The strategy here is to determine the nutrient status of the plant by plotting tissue values over time to ensure that a fertility program is on track.

For example, when growing a cannabis mother stock crop, a grower could collect samples monthly during the time the plant is developing prior to taking cuttings. This would provide valuable information to ensure that plants contain adequate nutrient levels going into the cutting season.

Another valuable strategy could be to sample the plants just before taking cuttings and then periodically over the cutting season. Typically, with other floriculture species, nutrient levels decline over time as cuttings are harvested. Knowing the status of your stock plants enables growers to modify their fertilization practices to the stock plants during the cutting season to help ensure the cuttings are nutritionally charged when growers take them from the plant.

A third monitoring strategy would be to periodically sample the cuttings taken from the stock plant during the cutting season. This will determine if nutrient levels are being maintained in the stock. This will also verify that the cuttings themselves have adequate nutrients.

Each of these nutritional monitoring strategies requires that growers sample each cultivar separately, as nutrient levels can vary with each one. In addition, if there are differences in the plant’s age or fertilization practices, cultivators should sample those blocks of plants separately.

Cultivators sampling plants for diagnostic analysis should sample them individually. To accurately diagnose a nutritional disorder, growers will need to take samples from the affected plant and/or symptomatic portion of the plant. For example, if the lower leaves display toxicity symptoms, then cultivators should sample those leaves. Because the critical lower deficiency ranges and toxic upper ranges for cannabis are not known at this time, if possible, cultivators should collect a “good” control sample to compare to their problem sample.

Understanding Testing Parameters

Generally, a leaf tissue analysis will include the following macronutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg). (Labs might not include sulfur (S) or may do so at an additional charge.) Tissue analysis also determines the following micronutrient concentrations: boron (B), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn). Some labs charge extra and require a larger sample amount for molybdenum (Mo) determination, and some will also test for sodium (Na) and chloride (Cl). While Na and Cl are not considered essential for plant production, some fertilizers or source water may contain these nutrients. Cultivators should check with the lab where they are submitting their sample to determine the elements tested and cost.

Sampling Procedure 101

The leaf tissue sample should be representative of the plant or production area being monitored or the problem cultivators wish to analyze. As mentioned above, growers should sample plants of different ages and varieties separately. The process includes:

1. Collecting leaf samples.

• For routine analysis, collect the most recently mature leaf. This leaf is typically three to five leaves down from the growing tip (Fig. 1 above). For a representative sample, take 25 to 30 leaves from five to 10 plants (Fig. 2).
• For diagnostic analysis, sample plants individually, taking leaves from the affected portion of the plant (Fig. 3). Again, if possible, sample a “good” control so that comparisons can be made.

2. Washing and drying leaves.

If the crop has been overhead watered or micronutrients have been foliar applied, gently wash the leaves in distilled water for 20 seconds to remove any surface contaminants. Dry the leaves with paper towels after washing, prior to packaging them.

3. Packaging leaves for analysis.

Send the samples in a paper bag or manila envelope to the commercial lab authorized to analyze cannabis samples (Fig. 4). Label the bag with your name and address. Contact the lab to verify if there are any special requirements for delivery and documentation under current legislation.

4. Delivering the samples.

Immediately send the samples to a lab certified in your state to conduct leaf-tissue analysis. Try to collect the sample at the beginning of the week so delivery will not be delayed over the weekend. If delivery time to the lab (or to a drying oven) is expected to exceed 12 hours, then it’s best to refrigerate or air-dry the samples.

At this point, nutrient sufficiency ranges for cannabis have not been developed for specific growth stage(s). Bryson and Mills (2014) published nutrient ranges for cannabis (Table 1 above). The database for cannabis nutrient sufficiency ranges is still a work in progress and will be further refined over time as scientific studies determine target nutrient levels over the crop's production cycle as well as critical deficiency and toxicity levels. Refinement of tissue standard ranges for cannabis has been a project being studied by the North Carolina Department of Agriculture and Consumer Services, Agronomic Division and North Carolina State University. Those refined values for cannabis mother stock plants grown in a greenhouse just prior to the stage when cuttings would be harvested are also listed in Table 1.

Conclusion

Leaf tissue analysis provides insight into the nutrient status of a cannabis crop. Tissue analysis results will help growers determine if their fertilizer program is on target by providing current nutrient levels in the plant. In addition, tissue testing is one of the best methods for diagnosing nutrient disorders in cannabis.

Brian Whipker, Paul Cockson, James Turner Smith & Hunter Landis are from the Department of Horticultural Science, North Carolina State University, Raleigh, N.C.

The terms cannabinoids, terpenoids and flavonoids may not have the same market appeal as indica or sativa. But many industry experts say these secondary metabolites hold more value to cultivators and their customers than common strain names.

In the September 2019 issue of Cannabis Business Times, senior editor Brian MacIver explored some industry myths and how science is changing the way cultivators make strategic decisions (see the cover story “The Science Void”). It’s a topic that CBT also explored during the 2019 Cannabis Conference.

Andrea Sparr-Jaswa, now science editor at CBT and sister publication Cannabis Dispensary, addressed some of these key issues as the moderator for a panel on “Science That Sells: Debunking the Sativa and Indica Myths and Instead Focusing on Terpenoids, Cannabinoids and Flavonoids” at the 2019 event, which featured Jeremy Plumb, director of production science for Prf Cultivar; Jeremy Sackett, founder and chief science officer of Cascadia Labs; and Dr. Dominick Monaco, general manager at GB Sciences Inc.

Here are some highlights from the panel discussion and a glimpse at what’s to come for Cannabis Conference 2020 taking place at Paris Las Vegas April 21-23, 2020. (Note: the following has been edited for length and clarity.)

On the Indica vs. Sativa Myth

Plumb: We’ve worked for a long time to try to be more relevant at both Farma and now at my role at Prf Cultivar, to try to … expose the ingredients. But the big issue is this: There’s morphology—like the plant structure. And when we look at narrow and broad leaves, from a plant morphology perspective, we can’t easily correlate that with the kinds of chemistry the plant produces. Really, this morphology was the basis for the original taxonomy.

And it’s gone through many waves. But the reality is, we’re in a new era where we have really distinctive features for phytochemistry on one side of the equation and then distinctive features for the morphological development of the plant on the other. But the giant issue happens when we try to connect the two. And really, [we] can never say that the narrow-leaved sativa plant is producing these focusing and euphoriant effects. That’s really going to come down to the molecules and the inventory and the chemistry in that plant.

Sackett: We’ll never find this perfect archetype of (indica/sativa) in the commercial market now. There’s a third category that’s often used, which is “hybrid.” The problem is … they’re all hybrids. These categories that have become popularized … are a bit unfortunate. You see … we have this moment in history to really change people’s lives with the inventory of phytochemistry, [and] we’re seeing really unfortunate labeling of the ingredients or misrepresentations altogether.

Sparr-Jaswa: Yeah, hybridization in the market and just this constant evolution of perpetuating new genetics—which is incredibly exciting—has completely rendered the [indica/sativa] dichotomy meaningless.

On Data Transparency and Targeted Effects

Monaco: If we don’t actually start collecting that [phytochemical] data, we don’t know if it’s actually having effects on therapeutic value for our patients or our customers. There could be a phytol, a sterol, an ester in there that’s causing all of these actual great therapeutic effects. Metabolomics [the study of metabolites’ effects on cells] is definitely where we’re going to find out exactly where the plant and body meet. We always talk about seed-to-sale, right? But we need to talk about seed-to-outcomes … because that’s where we’re going to get all of this actual data … where we’re going to push this forward.

Sackett: And, you know, that outcome at this juncture, as you mentioned, is really patient-based and empowering the patient or adult consumer to really understand what they are consuming. It just takes a little bit of motivation on the retail end. And then, hopefully, empowering the consumer to start tracking their outcome based on these sets of terpene and cannabinoid information that they now have.

Plumb: [Data allows us to] really meet people’s needs and take care of them in a more targeted way. … It always comes back on us to actually report and collect that data in a wholehearted way—to make sure it’s transparent and make sure that it’s not adulterated in any way, and that it’s analyzed correctly. Because, you know, if we start correlating things that aren’t correlatable, then we’re back to square one.

On Navigating Environmental Effects on Phytochemistry

Plumb: The reality is, if you are a producer as I am, you would see an unbelievable range of phytochemistry from one plant as a result of small changes in the environment. So, the kinds of things that contribute to affecting the secondary metabolite profile of drugs the plant is making include: temperature, relative humidity, light intensity, light wavelength, frequency of irrigation, nutrition programs, harvest timing—all sorts of things beyond the genetic material itself.

… So, for people who advocate sun-growing—which I am a huge fan of—we need to absolutely ecologically produce cannabis as … our carbon footprint scales. … But, on the other hand, we really need targeted effects and plants that can produce consistent arrays of phytochemistry in order to meet diverse people’s needs. So, there’s a really important role to play in controlled environment agriculture—in precision agriculture.

Monaco: You know, having cultivated 1.5 million grams every year out of our local Las Vegas facility, I can attest to the fact that it’s very difficult to get batches to be the same. We’ve noticed variance from room to room, time of year. … And having that laboratory data to come and back-end your actual production data to say, “OK, so my VPD went off here or my light shut off here or my CO2 went off and I had to switch out a tank for that day.” ... Knowing those kinds of things and then correlating it with the actual laboratory data is absolutely key if you want to fine-tune your operation.

On Nomenclature and Setting Consumer Expectations

Sackett: And speaking to the standardization of testing labs … there are many national organizations working to set those standards. … The general quality practices of any laboratory are consistent to a food laboratory, a pharmaceutical laboratory. But I’ve sat in rooms where [strain] names were changed just because the marketing team thought it would sell better under this name. I think ... what is in that name is really those phytochemicals. Using that profile to navigate both consumer choices as well as those breeding and cultivation choices is super important.

Plumb: We’re still at a moment where there is an incredible amount of genetic diversity. … And we have an opportunity to actually do an honest inventory and start to represent the products more accurately to consumers. So clearly diminishing the relevance of the strain name is a fundamental part of that and really moving forward the chemovar … is really the most important thing I see happening in terms of being more relevant to a mass market.

Sackett: Moving a product forward with those different claims of experience is a little bit early in my opinion. … And, ultimately, a dream that I have is that somebody can walk into a retail shop and be drawn to a terpinolene-dominant section, a caryophyllene-dominant section, a pinene-dominant section and have those grouped together and be able to make better choices.

So, I really think that we’re at a place where it’s just going to take a while, and we have to be humble and use great science and collaborate and be mature as an industry. And recognize what we don’t know and where we have to go to be able to serve the most people at the deepest level.

Jonathan Katz is managing editor for Cannabis Business Times and Cannabis Dispensary magazines.

Mergers and acquisitions are now commonplace in the cannabis industry. In the U.S., multistate operators (MSOs) can rapidly become dominant players by acquiring licenses or functioning operations in every legal state. Even smaller businesses have reason to expand operations within individual states to meet demand or prepare for impending federal legalization.

If not done correctly, however, acquiring or expanding to multiple sites can leave cannabis companies with excess expenses, inefficiencies and compliance issues. Managing numerous independent cultivation sites that have little in common is akin to herding cats: It’s a tricky exercise, and a few inevitably veer off course from the company’s core principles. Companies that manage multiple grow sites (and those that will soon find themselves with that responsibility) should consider the following advice to ensure their efforts work toward a successful and profitable endeavor.

1. Select site managers carefully

MSOs need a competent individual at the helm of each site to execute the company’s cultivation strategy and help guide the entire team toward hitting production targets. The person running day-to-day cultivation operations can make the difference between a successful grow site and a wasted investment. The type of grow site should strongly influence the kind of manager a cultivator selects.

For instance, most MSOs pursue a mixture of growing strategies, whether indoor, greenhouse and/or outdoor. While there are plenty of similarities in growing cannabis in any situation, the skill set required to successfully manage commercial cultivation can vary greatly depending on the environment. Consider, for example, a cannabis business that has been cultivating indoors but is now seeking to grow hemp outdoors. While it may be tempting to promote from within, placing an experienced indoor grower in the middle of a hemp field may not be a wise choice.

The process of cultivating cannabis indoors is quite different from open-field crop management. Indoor growers are usually concerned with environmental factors such as grow-light performance, and humidity and temperature management. With outdoor cultivation, none of that matters. Outdoor growers are more concerned with damaging weather, pesky animals and using the right tractor implements. The jump between these two work experiences is quite vast, and hiring for experience in these instances could make the difference between a successful operation and a costly learning experience.

2. Be available

Open communication and regular site visits are critical tools in the successful management of multiple grow sites. If a company’s cultivation director never shows up, won’t return email and seldom answers the phone, site managers who rely on his or her leadership will be forced to go it alone. Apart from the potential deterioration of the cultivation program, this situation could foster an adversarial relationship between the site manager and the director of cultivation. Avoid this situation by making yourself available, both on-site and remotely, to all site managers.

Key employees should feel empowered to communicate with their boss, regardless of the issue. Since site managers and section growers spend 40 or more hours each week tending crops and managing production, they have their fingers on the pulse of what’s happening at the grow site. A trusting and open relationship will increase the chances of catching problems early, before they lead to a crop loss. Cultivation directors who are constantly on the move should consider holding virtual office hours to ensure communication lines remain open.

Talking is important, but it’s no substitute for on-site visits. To truly understand what’s happening with a crop, a cultivation director needs to see, touch and sometimes even smell what is going on. Site visits provide this opportunity, as well as a chance for training, troubleshooting and employee feedback. If things aren’t going so well, site visits also can boost team morale. A site visit every two weeks is ideal—more frequently might be overkill, while less frequently may allow potential problems to spiral out of control.

3. Be consistent across all sites

Strive to have every cultivation site operate as similarly as possible, much like a franchise store or restaurant. With a franchise, every site and every experience is identical, regardless of location. Cultivation operations at multisite grow-ops should be no different. The more cultivation sites resemble one another, the more productive and cost efficient the entire company will be.

Production is streamlined when you don’t have to reinvent the wheel at each site. Crop scheduling is easier if the same genetics are grown at every location, and troubleshooting is simplified when all sites use the same growing method, equipment and inputs. Company-wide standard operating procedures are easier to write and enforce when each site follows the same processes. Shuffling growers between sites to fill staffing shortages holds little risk if there are no major differences between cultivation sites.

Critical activities, such as purchasing and facility maintenance, also can benefit greatly from the standardization of all grow sites. If each facility uses the same cultivation materials, purchasing can be centralized to take advantage of bulk discounts. And, if one site runs out of an important item, there is the option to borrow from another site instead of incurring the downtime associated with waiting on an order. Maintenance of critical grow equipment, such as trim machines or dehumidifiers, is easy to schedule and perform when all sites use the same manufacturer and model.

4. Encourage and provide cross-training

A company with multiple grow sites can be an excellent learning platform for the entire cultivation team. Oftentimes, growers get so immersed in their individual cultivation challenges that they seldom come up for air to gain a fresh perspective. Visiting other facilities within the same company can help growers break out of their daily routines and provide new ideas for tackling common issues. Learning is streamlined since growers can gain valuable knowledge from their coworker’s lessons without having to commit the same mistakes themselves.

Short visits or work exchanges between growers at different sites can be especially insightful when indoor growers spend a few days at a greenhouse operation or vice versa. While the specifics of growing may differ between each site, the challenges that growers face are universal: Pest infestations, disease pressure and nutrient problems plague every kind of grow operation. Seeing firsthand how growers at other sites tackle these issues can help strengthen the visiting grow team’s capacity to prevent or mitigate similar problems at its home site.

Cross-learning also can benefit new employees. If one site stands out from the rest in terms of efficiency or quality, select that site as a training center or boot camp. Have new recruits learn the ropes through orientation and hands-on training with experienced staff. This process will ensure consistent training and help ensure company-wide harmonization of protocols, policies and culture.

5. Be suspicious when ‘everything’s fine’

If feedback from one or more site managers is that “everything’s fine,” cultivators may be tempted to skip their regularly scheduled site visit. This would allow them to catch up on some much-needed office time or spend extra days at a site that may be struggling. They may also revel in the fact that their production sites are becoming more self-sufficient and that the workers they have put in place are doing their jobs.

But walking a crop that nobody is concerned about is just as important as walking a crop that everyone is concerned about. Cultivation directors typically have experience growing commercial crops and bring a seasoned and valuable perspective to the job site. They are well aware that although things are not bad now, conditions may be ripe for creating issues that are not obvious to others, and their expertise can help prevent these problems from coming to fruition.

For example, it’s common to find plants that are too dry at the end of the day. The grower may be afraid of adding too much moisture to the growing environment late in the day, or the plants may be growing rapidly, and a previous irrigation simply is not enough to hold them over. Damage may not be visible now, but based on experience, cultivators know that chronically dry plants can result in leaf damage, reduced productivity and increased susceptibility to insects and disease. If dry plants are noticeable during a walk through, a cultivator’s intervention in this scenario can help prevent this situation from damaging a crop that no one is concerned about.

Just because the site manager or section grower is content doesn’t mean that cultivation directors should be, too. By staying engaged with the activities at each site, cultivators can minimize M&A integration challenges and maximize bottom-line opportunities.

Ryan Douglas is the owner of Ryan Douglas Cultivation, LLC. He has worked in commercial horticulture for 20 years and specializes in legal cannabis start-ups.