Not surprisingly, the whole mushroom growing cycle begins with a good spawn. Now there is more than one way to get a happy mycelium, but it is important to note that it is a living thing. Like everything else, it needs water, food, and air. 

So does it hurt to remove the bad spawn either due to being contaminated or because it does not show adequate resistance? Especially since most of the time, it is our fault that the mycelium does not work as it is supposed to.

We could get everything from water content to substrate synthesis and still not get the desired result because we refused to find a suitable recipient for our mycelium. In a production scheme, a penny saved is a penny earned, but how much money do we all make using bad spawning bags and discarding five to ten percent of the production?

What makes the perfect mushroom grow bag?

What makes a good all in one grow bag is a bag that creates an ideal microclimate for growing mycelium, a bag that allows oxygen to enter and carbon dioxide to escape. This is a bag that eliminates the transfer of contaminants and of course, a filtered breathing bag.

The location of the filter is one aspect of the breathable bag. Most bags have a filter patch with several or a large needle holes. While this is a great way to provide a gas exchange for the top of the seed, it will not allow carbon dioxide to be emitted from the bottom of the bag.

Research has shown that the carbon dioxide concentration in the lower parts of filter patch bags is ninety percent higher than in the head area, that is, air pockets above the substrate.

This is damaging to the growth of the mycelium, as it can form a crust on the substrate, further restricting the flow of oxygen and carbon dioxide. On the other hand, a well-distributed filter that touches the spawn helps to remove excess heat and carbon dioxide.

It also provides oxygen to the mycelium, which is essential for the digestion of nutrients in the substrate. 

Filter material is another important aspect for both gas exchange and safety. In general, there are two types of materials, woven and non-woven. Woven material is defined by its pore size, which means that any particle smaller than the pore size can potentially pass through the membrane. 

Nonwoven filters work differently. Like the HEPA filter, the randomly arranged fibers will steadily reduce the kinetic energy of the moving particles until they are trapped in a three-dimensional maze. 

Performance is determined by the depth of the filter or the distance a particle must travel to pass through the filter; the greater the distance, greater the efficiency. It is quite critical to get the right filter.

The third and final factor to consider is the filtration surface. Depending on the mushroom you are trying to grow, you may want more or less gas exchange. 

It is associated with the incubation time. Substrates incubated for more than a month benefit from a small amount of gas exchange. It also limits the total loss of water in the substrate, which is important for the formation of the fruit body.

It is a shame to go through the hassle of getting everything right, but not your spawn bag. Invest in a good spawn bag. Find out what suits your production method and get best results.