Time and Dosage Related Kinetics of Cannabinoid and Flavor Extraction in Dry-Hemped Beer

Industrial hemp (Cannabis sativa L.) is a close botanical relative to hops (Humulus lupulus L.) and has been investigated as an alternative to hops in beer flavoring. Following the 2018 U.S. farm bill, which facilitated the legal use of low-tetrahydrocannabinol (THC) hemp, markets grew rapidly with potential applications in food systems. Hemp flower (inflorescence) contains both some of the same aroma compounds found in hops, as well as compounds with similar characteristics, but are notably lacking in bittering acids. However, they also contain concentrations of cannabinoids which are restricted in food products, especially alcoholic beverages like beer. Cannabinoids are known to have low solubilities in water; however, the extraction of cannabinoids from hemp into aqueous water-ethanol beer matrices have not been extensively researched. In this study, a floral hemp variety ‘Wife’ was assessed in a process modeled on dry hopping using a model beer. Both the effect of increasing quantities of hemp added to the beer (dosage) and extraction of compounds over time (duration) were assessed. A commercially available hop variety ‘Cascade’ was also used to further compare the effects of dry hemping to dry hopping. Cannabinoid content and volatile compounds were assessed throughout the extraction processes. Most of the extraction process occurred in the first 24 h. At dosages greater than 8 g/L cannabinoid concentration plateaued, but aroma compounds continued to increase with dosage (with reduced extraction efficiencies). Overall, hemp flower imparted many volatile terpene compounds into beer, with cannabinoids at levels well below regulatory limits.