Essentially, grow bags are plastic containers filled with substrate (a mix of organic materials that provides nutrients for mushroom mycelium to grow on) then inoculated with spores or mycelium. The mycelium grows in the bag forming mushrooms that can then be harvested. The bag itself is sterilized to kill any contaminants and is then used as a self-contained growing chamber.
Mushroom bags are often used as a simple alternative to using a grow tent or a monotub, but can also be combined with other enclosed grow chambers such as a BoomRoom martha tent. To use as a spawn bag, simply inoculate the bag with your preferred mushroom spawn culture and let it colonize in a dark space for 2-6 weeks. When fully colonized, cut a slit into the side of the bag above the filter patch (we suggest matching the width of the slit to the width of the filter patch). This will help prevent side pins from forming in your block and can be used as an easy way to keep the mushroom block moist.
The 0.2 micron filter patch on our ShroomTek bags allows for the optimal amount of air exchange while blocking contaminants like mold spores and bacteria from entering the bag. This is an important feature since most bags are sterilized in an autoclavable machine that subjects the bag to very high heat and pressure for hours at a time. Without a filter patch, these contaminants would melt through the bag contaminating your spawn culture and growing mushrooms. Psilocybin grow bags