What are the traditional methods for preserving edible mushroom spawn

When edible mushroom mother cultures reach their expiry date, they must generally be used up; even if they cannot all be used, they must be transferred to new tubes again, or stored in a refrigerator, otherwise they will age and cause difficulties for mushroom growers during production. The reason mother cultures are difficult to preserve is that their mycelium grows on potato medium; because potato medium is rich in nutrients, the mycelium grows especially vigorously, and without a refrigerator it is very difficult to control mycelial growth. In this regard, the author introduces to mushroom growers a traditional method of preserving spawn, which can be stored at room temperature for 6 months without aging. The method is as follows:

Transfer the mother culture into a spawn stock culture in a contamination-free area. After the stock culture is made, when the mycelium has grown to half of the stock culture bottle, in an inoculation box or inoculation room, or in a contamination-free area, remove the cotton plug or kraft paper sealing the mouth and tie it tightly with two layers of plastic film to deprive it of oxygen. When the mycelium has consumed the remaining oxygen in the bottle, it stops growing or grows extremely slowly; even if the mycelium grows to the bottom of the bottle, it cannot shift to the reproductive growth stage because it cannot breathe without oxygen. In this way, the goal of preserving the mycelium so that it remains full of vitality without aging can be achieved. However, before use, the seal at the bottle mouth must be loosened (but the bottle mouth must not be opened) to let it breathe oxygen for one to two days, so that the mycelium has vigorous vitality before it can be used.

This method is practical and simple, and is especially suitable for mushroom growers who have just started growing mushrooms, as well as for those who have no spawn storage equipment. As long as contamination-free operation is observed, it will bring great benefits to mushroom growers when making spawn.