A drop of liquid culture can technically be used to inoculate grain but the more you use, the faster the colonisation time will be. 10ml of liquid culture is enough to inoculate two of our grow kits. You can also use 10ml of liquid culture per grow kit to speed up the colonisation process if you like. We recommend using no more than 10ml per kit as it can cause excessive pooling of water in the bag, creating bacteria.