To avoid premature deterioration of raw products such as spices and herbs or products produced with these ingredients, the product or material is sterilized by exposure to elevated pressures and temperatures for a predetermined time. The sterilization process comprises a multiplicity of chambers whereby a product is introduced to the first chamber, pressurized, transferred through a series of sterilization chambers while exposing the product to the sterilization environment of the chambers for a predetermined time, then depressurized in a depressurization chamber. When using a moist sterilization fluid, a drying chamber is attached to the depressurization chamber to remove excess and undesirable moisture from the product.
