What is pasteurisation?
The process whereby organic materials are treated to kill plant infections and diseases and organisms infectious to animals (pathogens) and weed propagules (seeds, and living plant tissue otherwise able to grow again). Effective pasteurisation via an aerobic and thermophilic (>55C) composting or equivalent process, destroys weeds, seeds and plant/animal pathogens that may have been present in the original organic materials. In most instances pasteurised products should be considered superior to shredded plant material products (e.g. leaf mulches), because non-pasteurised products increase the risk of spreading weeds, seeds or plant/animal pathogens. Soil conditioners which have only been pasteurised and are then available for immediate sale, are not mature composts and continue to decompose following use. Thus, pasteurised soil conditioners cannot be incorporated in excessive quantities into soils, as increased oxygen consumption from decomposition processes in the root zone can delete
