A multi strain culture is a mushroom culture that contains an array of spores that could each develop into different, unique mushrooms with their own traits.
Whenever a print or spore syringe is used to inocculate the substrate, it is called a multi strain culture. The ‘different’ spores will germinate inside the substrate, and form mycelium. A multispore culture can be the reason that many mushrooms in the same flush have different looks and develop at a different growth rate.