Used with kind permission of the Australian Mushroom Growers Association

The raw materials for growing muhrooms owe little to sophisticated technology. Science hasnt come up with anything quite as good as old fashioned substrate. Mushroom substrate is made from wheat straw and organic material from racehorse stables. It provides the basis of the substrate that has to be made every week to keep the mushroom farm in production.

Other organic ingredients are added to the substrate which include cotton seed meal and hulls and large quantities of chicken manure. All these recycled materials are mixed together, watered and left to compost for a week. The natural fermentation process takes place in stacks, which are turned every two days. New tunnel substrate technology is being used to improve compost quality. The temperature inside the substrate is about 80 degrees Celsius. The substrate is put into tunnels and steam heated to kill competitor moulds that could damage the crop.

Spore, the seed of the mushroom, is used to produce grain spawn under sterile, germ-free conditions. The mushroom spawn is then added to the substrate. Fields have given way to sophisticaed rooms in which the environment is precision controlled to simulate ideal natural growing conditions. Constant checks ensure that the temperature and humidity are kept at the right levels, while the spawn multiplies in the substrate. There is a certain magic and mystery about mushrooms. Despite the ever-continuing research by scientists, no one knows for sure what makes mushrooms grow. The only certainty is that they will not normally appear in commercial quantities until a surface of peat moss is put on the mushroom compost. The process continues in the growing room and in about 12 days the first mushrooms appear.

At every stage of the process, the environment is precision controlled and strict hygiene measures are rigidly enforced. The mushrooms are ready for harvest in three weeks. The growing process is unusual because a mushroom doesn't have leaves or a normal root system. Nor does it need sunshine or chlorophyll, the means by which most plants make their food. They are a hetertrophic organism. A funghi.

Harvesting has to be done by hand. Each bed yields up to 3 crops, or "flushes" of mushrooms over a period of four weeks. The used substrate is sold mainly to landscape and home gardeners. The mushroom industry boasts that it uses only recycled materials and wastes nothing.

As fresh mushrooms are a modern, tasty and nutritious food, Australians are eating more each year. A big investment in controlled environment mushroom farms has ensured that fresh mushrooms are available every day of the year to meet consumers needs.