Mushrooms such as oyster mushrooms (Pleurotus ostreatus) are usually grown in plastic bags filled with organic material that may include organic farm wastes. That material must be sterilized (heated to temperatures above 100°C) or pasteurized (heated to a lower temperature, 60°C or higher) to prevent contamination by germs, viruses and fungal spores. However, sterilization and pasteurization are challenging for small-scale farmers because of the energy requirements. Normally, small-scale farmers use a drum sterilization method, during which water is heated until it boils. Farmers must buy or collect the firewood to heat water (an expensive and/or labor-intensive task). Charcoal is even more costly to buy or to make. Also, results of drum sterilization can be inconsistent, depending on the device used and quality of the fire wood.
The new, easy-to-build piece of pasteurization equipment introduced in this article is inexpensive, long-lasting, easy to prepare, and does not need fossil fuel energy. The pasteurization process does not need monitoring, so it requires less labor.
The aim of this article is to encourage other development workers and local farmers to continue these early experimentations to improve the device or other similar ones so that they become useable in their own different environments, with an aim of helping small-scale farmers save energy and money when growing mushrooms.