When venturing into the world of mushroom cultivation using bags, you'll encounter a variety of options. One key decision involves the filter patch, a crucial element for gas exchange while preventing contamination. But what's the difference between T filters and A filters? Let's break it down.
Micron Matters: Filtration Power
The main distinction lies in the pore size of the filter. Here's the key difference:
T Filters (often labeled T): These boast a finer filtration level, typically around 0.2 microns. This effectively blocks most airborne contaminants, including mold spores and bacteria.
A Filters (often labeled A): These have a larger pore size, usually around 0.5 microns. While they still provide some filtration, they allow for slightly better gas exchange.
Choosing the Right Filter for Your Needs
T Filters: Ideal for spawn bags, where maintaining sterility is paramount. The finer filtration minimizes the risk of contamination during colonization. However, the tighter weave can slightly restrict gas exchange. Examples:
Shiitake (for colonization stage only): While Shiitake mushrooms can eventually be fruited with A filters, the delicate spawn needs the extra protection of a T filter during colonization to reduce contamination risks.
Maitake mushrooms: These prized mushrooms also benefit from the high filtration of T filters during colonization.
Reishi mushrooms: Like Shiitake, Reishi mushrooms require a clean environment for spawn growth, making T filters a good choice.
A Filters: Better suited for fruiting substrate bags. The larger pores allow for better gas exchange, crucial for mushroom growth. However, they offer less protection against contamination. Examples:
Oyster mushrooms (fruiting stage): Once the oyster mushroom spawn has colonized the substrate, A filters provide the ideal gas exchange for fruiting bodies to develop.
White Button mushrooms: These popular mushrooms require good air circulation for fruiting, making A filters a good option.
Cremini mushrooms: Closely related to White Button mushrooms, Cremini also benefit from the air exchange provided by A filters.
Enoki mushrooms: These delicate mushrooms fruit well with the moderate gas exchange and contamination prevention offered by A filters.
Other definitions:
Spawn Bags:
Purpose: Spawn bags act as the starting point for mushroom growth. They contain sterilized grain (like rye or wheat berries) inoculated with mushroom mycelium (the vegetative part of the fungus).
Function: Inside the spawn bag, the mushroom mycelium colonizes the grain, feeding off the nutrients and growing stronger. This colonized spawn is then used to "seed" the substrate bag.
Appearance: Spawn bags are typically smaller and more opaque than substrate bags. They may have a micro-filter patch for gas exchange while minimizing contamination.
Substrate Bags:
Purpose: Substrate bags provide the food source and environment for mushrooms to fruit (grow the visible above-ground mushrooms we eat).
Contents: Substrate bags contain a mixture of materials like straw, sawdust, wood chips, or a combination, often pasteurized or sterilized to eliminate competing organisms.
Function: Once colonized spawn is introduced to the substrate bag, the mycelium network continues to grow, eventually producing the fruiting bodies (mushrooms) that we harvest.
Appearance: Substrate bags can be larger and more transparent than spawn bags. They may also have a filter patch, typically an A filter for better gas exchange during fruiting.
Here's an analogy:
Think of spawn bags like starter dough. It contains the active culture (mycelium) that needs to grow and multiply before it can be used.
Substrate bags are like the bread pan. It provides the necessary environment and nutrients for the dough (mycelium) to rise and eventually bake into a delicious loaf (mushrooms).
Happy mushroom growing!
Love, GBS