A method and apparatus for pasteurizing and drying marijuana plant materialsusing a microwave-vacuum chamber. Thepasteurizing and drying are carried out with no use of ionizing radiation andwith rapid drying. Pasteurization is done at a temperatureand for a time period that are sufficient to reduce microorganisms to anacceptably low level, while not significantly reducing thepsychoactive compounds in the material. In the process, the pressure inside avacuum chamber is reduced to a first pressure less thanatmospheric. The material is maintained in the vacuum chamber at the firstpressure at a pasteurizing temperature while irradiating thematerial with microwave radiation. The pressure is then reduced to a secondpressure lower than the first pressure and the material ismaintained in the vacuum chamber at the second pressure for a time period at adehydrating temperature lower than the pasteurizingtemperature while irradiating the material with microwave radiation. Thepasteurizing and dehydrating steps can be done in the reverseorder.
