Abstract: A terpene extraction system and method of extracting terpenes from plant biomass are described. The plant biomass is derived from a Cannabis source plant, as one example source plant. A reactor assembly and one or more cold traps can be a part of the system, and can be involved in the method. The reactor assembly has a housing that receives the plant biomass, and has an agitator that moves the plant biomass in the housing, per an example. The cold trap(s) is situated downstream of the reactor assembly. A heater and a vacuum pump can also be part of the terpene extraction system, and can be involved in the method.