Drying, Curing Cannabis sativa L.: Implications for Moisture, Microbial Safety, and Chemical Quality

Drying and curing are critical postharvest processes that determine the safety, stability, and chemical quality of Cannabis sativa L. inflorescences. In commercial cannabis production, these processes are often based on empirical practices rather than quantitatively optimized engineering principles. Improper control of drying conditions can result in excessive terpene loss, undesirable cannabinoid transformations, and increased microbial contamination, particularly from yeasts and molds. This review examines current knowledge on cannabis drying, curing, and storage with emphasis on the relationships among moisture content, water activity, microbial safety, and chemical quality. Literature describing postharvest cannabis processing is synthesized alongside broader drying and food engineering research to evaluate how temperature, relative humidity, airflow, and drying duration influence moisture removal, terpene retention, cannabinoid stability, and microbial proliferation. Water activity emerges as a critical parameter governing both product stability and microbial growth, highlighting the importance of controlled drying and curing environments. The review also discusses how curing and storage conditions influence chemical and microbiological stability after drying. Current research gaps are identified, particularly the limited availability of quantitative models describing moisture transport and drying kinetics in cannabis inflorescences. The integration of engineering-based process control, environmental monitoring, and predictive modeling may improve the consistency and safety of cannabis postharvest processing. Improved understanding of these relationships will support the development of optimized drying and curing protocols that balance microbial safety with preservation of chemical quality in cannabis products.