Italian Oysters (Pleurotus pulmonarius) mushrooms have a amazingly soft texture with a somewhat sweet flavor. They're an aggressive species that will fruit quickly when given the opportunity.
What's a Live Culture? - A live culture allows you to skip spore germination and go right to expanding the living tissue.
Agar Wedge - An agar wedge provides the living tissue of a specific fungus attached to a small piece of agar. You can then place this wedge on a sterile agar plate to expand the fungus in preparation of growing mushrooms. This tiny amount of living tissue is more than enough to grow thousands of pounds of mushrooms. You simply expand the tissue onto an agar plate. Once that plate is fully colonized you then take wedges from that plate and place on to more plates.
Plate - A plate is simply a petri dish with a specific fungus growing on the agar gel within it. Plates are one step closer to growing mushrooms since you can inoculate grain spawn with them. Plates provide enough of the fungus to inoculate 2-3 quart jars full of grain spawn.