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.