Template:Mushroom cultivation
Liquid culture consists of a sterilized nutritious solution, usually a mixture of water and various kinds of sugars, which has been inoculated with fungus spores or mycelium. Once colonized, liquid culture is used to inoculate PF jars or Grain Spawn.
The advantages of using liquid culture instead of spores to inoculate your jars or spawn are that the cultivator no longer has to wait for spores to germinate, thus reducing incubation times by at least a week, and that 1cc or spore solution can be used to create an effectively limitless amount of liquid culture. Since spore syringes are expensive and the cultivator may worry about ordering spores to their house, creating gallons of liquid culture from 10cc of spore solution is definitely to be preferred.
Here is a tek about the basics of liquid culture. Here is a tek for creating liquid culture out of honey and water