In this episode of Cultivation Elevated, hosts Michael Williamson and Anders Peterson are joined by David Goodnack from Plant CO2 to discuss the crucial role of CO2 in cannabis cultivation, particularly in commercial vertical farming. They explore the technicalities of CO2 systems, focusing on the transition from small-scale home grow setups to large-scale commercial applications that use liquid CO2 stored in cryogenic tanks. David shares his insights on the challenges growers face in sourcing and designing effective CO2 systems and how his company, Plant CO2, was created to fill a gap in the industry. The conversation also touches on the emerging potential of direct air capture technologies, creative CO2 solutions like co-locating with breweries, and the importance of educating growers early on in the design process. Personal anecdotes from David, including his passion for surfing and skydiving, add a lighthearted touch to the discussion.

Introduction

• This episode is hosted by Michael Williamson and Anders Peterson, discussing CO2 design in vertical farming and its importance for cannabis and food production.
• Guest: David Goodnack from Plant CO2.

• CO2 in Commercial Cultivation:
  • CO2 is essential for plant growth, especially in commercial cannabis cultivation.
  • Discusses the importance of CO2 systems in sealed environments like indoor grow rooms.
  • Commercial systems use liquid CO2, stored in cryogenic tanks, compared to smaller, less efficient systems used in home grows.
• CO2 Distribution:
  • Importance of designing CO2 distribution systems to ensure proper levels in all grow rooms.
  • CO2 distribution must be precise to avoid creating microclimates within rooms.
• Liebig’s Law of the Minimum:
  • CO2 is a limiting factor for growth, but its impact is only significant when other factors (e.g., light, nutrients) are optimized.
• CO2 Equipment and Tank Rentals:
  • Discussion on CO2 tank sizes and costs (e.g., a 6-ton cryogenic tank can cost around $90,000).
  • CO2 companies make money through tank rentals and the price of CO2, which depends on delivery and distribution costs.
  • Options to rent or purchase tanks, but rental is often more economical.
• Challenges with CO2 Systems:
  • Challenges faced by commercial growers in finding the right CO2 systems, leading to the creation of Plant CO2 by David.
  • The importance of the right equipment to avoid issues with CO2 loss and inefficient systems.
• Direct Air Capture vs. Liquid CO2:
  • Introduction to direct air capture machines, which pull CO2 from the air and are currently less viable due to high energy consumption and costs.
  • Liquid CO2 remains the more reliable and cost-effective option for commercial growers at this time.
• Innovative CO2 Solutions:
  • Examples of creative CO2 solutions, like co-locating cannabis grows with breweries to capture CO2 from fermentation.
  • Discussion of using combined heat and power (CHP) systems to capture CO2 in greenhouses, especially in places like the Netherlands.
• Education and Market Gaps:
  • Education gaps in the cannabis industry regarding CO2 needs, with growers often neglecting CO2 systems until late in the design process.
  • David’s frustration with the industry led to the creation of Plant CO2 to provide better solutions and education for cannabis growers.
• Personal Insight:
  • David shares his personal interests, including his love for surfing and skydiving, and discusses the connections between engineers and hobbies like surfing.
• Contact Information:
  • David is easily reachable via his website, PlantCO2.com, where customers can get quotes within 24 hours.

This episode highlights the complexity of CO2 systems, the importance of proper design and equipment, and the emerging potential of new technologies in CO2 capture for cultivation.

This episode of Cultivation Elevated dives deep into the curing process of cannabis, exploring its critical role in achieving high-quality flower. Hosts Michael Williamson and Anders Peterson discuss the science behind curing, including moisture content, enzymatic activity, and ethylene gas production. They also examine best practices, common mistakes, and innovative techniques used in both small-scale and commercial settings to optimize terpene retention, potency, and overall product consistency.

Introduction

• Hosted by Michael Williamson and Anders Peterson from Pipp Horticulture.
• Episode focuses on curing cannabis, part of a three-part series on harvesting, drying, and curing.
• Discussion blends traditional methods, scientific advancements, and industry best practices.

Understanding Curing & Its Importance

• Drying vs. Curing: Drying is a rapid moisture reduction, while curing homogenizes moisture content.
• Curing enhances the terpene profile, reducing the “grassy” chlorophyll aroma over time.
• Enzymatic activity and degradation of compounds like chlorophyll play a key role in quality.
• Environmental factors like temperature, humidity, and light exposure impact the curing process.

Different Curing Approaches

• Some commercial growers treat the entire drying room as a curing space.
• Traditional methods include curing in bags, jars, totes, or turkey bags.
• Burping (controlled opening of storage containers) is used to release excess moisture.
• New technology is emerging, such as auto-burp systems and sensor-based monitoring.

Science & Variables in the Curing Process

• Ethylene gas plays a role in the ripening process (similar to bananas and tomatoes).
• Vapor Pressure Deficit (VPD) impacts moisture release during curing.
• Cannabinoid changes: Overexposure to oxygen converts THC to CBN, making cannabis more sedative.
• Environmental consistency is critical – differences in humidity, temperature, and air circulation affect the final product.

Challenges & Best Practices in Curing

• Different strains (cultivars) require different curing approaches.
• Sorting buds by size and density helps create consistent drying and curing conditions.
• Packaging matters – nitrogen purging was used in the past, but it sometimes reduced flavor quality.
• Commercial growers need to maintain uniform environments in trim rooms to avoid unintended drying during processing.
• Modified Atmospheric Packaging (MAP), commonly used in the food industry, could play a role in long-term cannabis storage.

Industry Insights & Future Research

• Many growers still rely on experience ("feel") rather than scientific testing.
• More research is needed on ethylene gas’s role in curing and optimal curing environments.
• Tobacco and food drying industries offer some insights, but cannabis curing is unique.
• Technology like Curepuck and sensor-based burping solutions could improve consistency.

Closing Thoughts

• Curing is the key differentiator between good cannabis and high-quality cannabis.
• The science behind curing is still evolving, and industry collaboration is needed to refine best practices.

In this episode, the hosts dive deep into the intricacies of cannabis drying, sharing expert insights on best practices, airflow management, and the common pitfalls to avoid. They discuss the importance of controlling temperature, humidity, and airflow to ensure consistent, high-quality drying. Key topics include the pros and cons of different drying setups like racks vs. carts, how to avoid microclimates, and the importance of maintaining a controlled environment. The episode highlights the often-overlooked impact of drying on the final product and offers practical tips for improving the process, from designing the drying room to understanding moisture management.

Drying Room Basics:

• The drying process is key to producing high-quality cannabis, and airflow is a critical factor.
• A drying room setup typically involves multiple people, with one or two focused on managing the drying process.
• Adjusting airflow is essential, especially during the "poofy" phase when the crop is wet and holding a lot of moisture.
• Over-drying can happen if fans are not positioned properly. Airflow should not be directed directly at the crop but rather across the room to avoid excessive drying.

Fan and Airflow Management:

• There’s debate about whether it’s better to push or pull air through a drying room.
• The ideal airflow design often involves drawing air through the room, avoiding direct fan placement on the crop itself.
• The design of a high-end drying room (e.g., Conviron Chambers) uses perforated walls to evenly pull air through the crop, enhancing consistency.

Carts vs. Racks:

• Racks, when compared to carts, offer better airflow as there is more space between tiers to circulate air effectively.
• The height of racks (12–18 inches between tiers) provides space for better airflow, especially around the thicker colas that retain more moisture.
• Carts, on the other hand, do not allow for as much airflow between plants, which can lead to uneven drying.

Drying Room Design:

• Proper drying room design should ensure minimal disruption to the drying process, such as ensuring fans are well-positioned and avoiding microclimates created by improper airflow.
• Lights should be kept off and doors kept shut to maintain consistent conditions inside the drying room.
• Sealing the room properly (including door sweeps and thresholds) helps maintain a stable environment.

Quality Control in Drying:

• A consistent, controlled drying environment is crucial for preserving the terpenes and quality of cannabis.
• Over-drying or improper drying can degrade the product and affect its final quality.
• Taking the time to measure and map out temperature and relative humidity (RH) across different areas of the room can help optimize the drying process.

Curing and Final Product:

• Drying and curing are interconnected, with the drying phase playing a major role in the final product’s quality.
• The podcast hosts emphasize that drying should not be overlooked, as it has a big impact on the product's outcome.
• They mention potential future research through the Cannabis Research Coalition to help improve drying techniques and share more data on the subject.

Closing Thoughts:

• The podcast encourages listeners to experiment and find what works best for their setup but also emphasizes the importance of following key drying principles for the best results.
• The hosts highlight that, while drying is a complex process with some subjective elements, good practices and attention to detail will lead to high-quality cannabis.

Podcast Episode Summary: Cultivation

The episode discusses efficient harvesting techniques and the importance of maintaining cleanliness and compliance in the cannabis cultivation process. Michael and Ahders share tips on improving speed and quality during harvest, such as the use of RFID scanning technology for tracking and compliance. One of the key points is the importance of cleaning up the cultivation room before starting to harvest to avoid contaminating the buds with particulates from the substrate.

They also talk about using air quality meters to monitor particulate matter in the air during post-harvest processing. Michael and Anders emphasize the role of the cultivation team in harvesting, noting that they are typically more connected to the crop and handle it with more care than post-harvest teams. The podcast also discusses the importance of keeping a steady workflow and ensuring no team members are left waiting for tools or supplies. The team shares their experiences with improving harvest efficiency over time and the benefits of avoiding harvests on Mondays and Fridays, recommending mid-week harvests for better staffing and monitoring of the drying process. Additionally, the conversation touches on labor productivity throughout the week and the benefits of keeping harvests within a single day to avoid complications during the drying process.

Harvesting Efficiency:

• Emphasizes teamwork during harvest, including "tag team" efforts for smoother and quicker processes.
• Outlaw Technology’s RFID scanning tool is highlighted for improving speed, accuracy, and compliance by linking with a scale.
• RFID scanning enhances inventory management and helps streamline post-harvest accuracy, reducing errors from manual data entry.

Cleanliness and Compliance:

• Stress on the importance of keeping the cultivation room free of particulates before harvesting to avoid contaminating the buds.
• Moving substrate or equipment during harvest can stir up particles that get on the flowers, affecting quality and compliance.
• Use of air quality meters to measure particulate matter in the air and validate room sanitation after harvest.

Harvesting Team Composition:

• Cultivation team is ideal for harvesting because they are most connected to the crop and take more care, reducing damage to the plants.
• Post-harvest crews tend to be less connected to the plants and may work less gently, potentially affecting quality.
• Compliance person tracks wet weights and labels harvested plants in the drying room.

Workflow and Steady Flow:

• Importance of a "water spider" role to move carts or racks between cultivation and drying rooms to prevent bottlenecks.
• Ensure no one is waiting on others for tools or equipment to keep the workflow steady.
• Example from a facility where initial harvest took an entire shift but improved to just a few hours after a few months.

Optimal Harvesting Days:

• Avoid harvesting on Mondays and Fridays to ensure adequate staffing and monitoring.
• Harvesting on Tuesdays or Wednesdays is ideal to ensure quality monitoring during the critical 24-48 hours after harvest.
• Harvesting should ideally be completed in one day to maintain proper drying conditions.

Labor Productivity:

• Mondays tend to have slower productivity due to the start of the week.
• Tuesdays and Wednesdays are optimal for productivity (good to great).
• Thursdays and Fridays tend to have reduced productivity, with Friday being especially prone to staff calling out.