Spawn is mycelium, the precursor to mushrooms, grown onto a sterile substrate such as whole oats. Much like seeds are to plants, spawn is used to cultivate mushrooms in large quantities. At FORIJ we offer two types of spawn: grain spawn and sawdust spawn (fruiting blocks).
Grain spawn is used by indoor cultivators as a precursor to fruiting blocks (or sawdust spawn). Once fungi have finished colonizing a whole grain medium, this resultant grain spawn can be broken up and used to inoculate large quantities of sawdust fruiting blocks, which mushrooms can then fruit out of. Cultivators rarely fruit from grain spawn (“in vitro”) because grain is so nutrient-dense that it poses a huge risk for contamination by other unwanted molds and bacteria in the air. FORIJ grain spawn is made from whole oats using a special recipe tested for fast colonization and ideal moisture. The oats are organically sourced from local Canadian oat farmers. All our grains are pressure cooked at 15PSI until made sterile.
Our mycologists and mushroom farmers have tested different types of grain for their colonization speeds and ability to maintain moisture levels through varying shelf lives before inoculation. Oats provided the fastest colonization times compared to other grains such as millet, milo, and rye berries. The FORIJ ethos also places emphasis on reducing carbon footprint when possible--that’s why we grow mushrooms, because they’re delicious and great for the environment! Oats are a Canadian-sourced seed while millet and milo are only grown in warmer climates such as Texas and the southern US, making them less available to Canadian mushroom markets and more carbon-taxing through imports.
Sawdust spawn, or a “fruiting block” is used to fruit mushrooms (of a hardwood-loving species) after being inoculated with grain spawn. Once fungi have finished colonizing a supplemented hardwood sawdust medium, the bag containing the resultant sawdust spawn can be used as indoor grow kits to be sliced open for the mushrooms to fruit. They can also be used to inoculate outdoor straw beds or logs. Our sawdust spawn is made from hardwood sawdust pellets hydrated to field capacity and supplemented with 20% wheat bran. All our blocks are pressure cooked until sterile.
Hardwood sawdust pellets provide an excellent growing and fruiting medium for most species of culinary mushrooms. Hardwood is significantly less nutrient-dense than whole grains, therefore, it poses a much lower threat for contamination compared to grain spawn. Bacteria are significantly less inclined to eat up hardwood sawdust compared to wood-loving fungi. Our team of mycologists tested a variety of different formulas and hardwood pellets supplemented with wheat bran provided the fastest results with the best yields.
Yes! In nature, once mature, mushrooms will release thousands of spores which are scattered by the wind, water, insects, animals, etc. Each spore has a poor prospect of successfully propagating and becoming a mushroom because ideal environmental conditions for fruiting are few and far between. Since only a small portion of spores are successful, large quantities released from each mushroom are essential to ensure maintaining the population. FORIJ mycologists have been trained to create multiple colonies (monocultures) on agar plates by triggering spores to germinate on sugar medium. These monocultures can then be expanded, tested and stored long term to inoculate grain spawn, petri dishes, and liquid cultures.
The spawn sold at FORIJ is produced in our lab. The journey from spores to spawn can take multiple routes. Spores can be germinated on an agar plate, creating multiple colonies which can then be expanded and tested. The mycelium, from a single colony, will spread out covering the agar plate. At this stage, a chunk of mycelium on agar can be cut from the agar plate and used to inoculate a sterile grain bag. Mycelium will spread throughout the sterile grain, producing grain spawn. Once consolidated it is ready to transfer to the fruiting block. For some species such as Lion’s Mane that only require a small amount of oxygen to trigger fruiting, a liquid culture can be created before inoculating into the sterile grain. Liquid cultures are created by inoculating sterile malt extract broth with mycelium from a single monoculture.
The colonized sterile grain can be broken up and used to inoculate a sawdust fruiting block, often with a ratio of 10-15% grain spawn. After mixing up the contents, mycelium spreads throughout the sawdust block, consuming nutrients to fully colonize the hardwood medium and turn into sawdust spawn. Once the sawdust spawn is consolidated, the bag can be cut and mushrooms can fruit.