Colonised Bags stored

Benefits of Prolonged Storage of Colonized Milky Mushroom Substrate

When cultivating mushrooms on a tight budget, its often-common practice to use mushroom varieties suitable for the local climate. In the hot and humid climate of Mangalore where I grew up and set my mushroom farm, Milky Mushroom always topped my must grow list of mushrooms.

Monsoon Rain


We used usually use hot water pasteurized paddy straw as the substrate material. To get the water content of the straw just right we would first drain most of the water from the straw and then spread them on plastic tarps under the sun until they reached the required amount of water content. This was not always the most convenient method especially during the rainy monsoon season where there was not enough sunlight and you could never tell when it would start to rain. We lacked the suitable infrastructure and equipment to dry the straw any other way at the time.



One of the work arounds we came up with was to stock up on pre-colonized substrate bags in the month preceding the monsoons. The advantage was that all we would need to do was open said bags and apply a casing layer within the mushroom growing room. The elevated humidity in the air due to the rains helped as well as this reduced the need of frequent watering.

As long as the colonized bags were kept in a clean place away from sunlight and contaminants, we found that the bags could be stored for an additional 2 months after full colonization. We did however experience the occasional mushrooms rupturing the bag and giving a flush during storage but for the most part there was not any mushrooms.

This method had several advantages:

  1. Bags were always readily available and required very minimal labor- just casing and shifting to the growing house- in order to cultivate mushrooms.
  2. The flushes of mushrooms were much larger as the mycelium had more time to digest the substrate and make use of the nutrients. Any loss in water weight of the substrate could be made up by dunking in cold water for a few seconds.
  3. You would not need to depend on availability of sunlight or the weather to process the substrate.
  4. It is possible to case only the number of bags required so that mushroom production meets the current market demand. The colonized substrate would have a longer shelf life compared to the harvested mushrooms.
  5. It is possible to sell the colonized substrate to hobby mushroom cultivators, removing the need for cultivation and getting quick income.
  6. You can temporarily halt mushroom cultivation when required, for example incase maintenance to the growing house is being done but continue with other mushroom activities so that the labor does not remain idle.

There are a few disadvantages to this method as well:

  1. You need suitable infrastructure and space to store the colonized bags until they are needed.
  2. There is risk of rodents, insect pests and contamination getting into the bags if the storage area is not proper.
  3. With larger volumes of the colonized bags, it is difficult to spot any individual bags that might have contamination and there is always the possibility of the contamination spreading to the neighboring bags.
  4. Metabolic wastes tend to buildup in the bags due to inactivity of the mycelium. This could impact mushroom yield later when the bags are used. We could counteract this by dunking the bags in cold water for a few seconds prior to casing. This removed the metabolic wastes.
  5. As the colonized become more and more old, the bag might show signs of decomposition, usually into a muddy goo. So, it is best to use the bags as soon as needed and not keep for more than 2 months.
  6. There is the possibility that the strain of mycelium in such bags might have reduced vigor due to prolonged in activity. In case of using harvested mushrooms for tissue cloning to propagate the strain, it is always best to take mushrooms from freshly colonized bags instead.

Please note: An unusual phenomenon we observed when storing milky mushroom substrate bags like this was that in case the bags were exposed to sunlight; these areas would undergo excessive pinning underneath the plastic and would form lumps almost akin to a tumor.


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