Days 1-5: white threads spread from each grain. Days 5-12: threads meet and the straw colour fades. The folder expects the whole bag white in 15-25 days. The manual sets a hard rule: never open before 16-18 days, except P. membranaceus and P. djamor var. roseus, which fruit through the holes within 10 days.
Trouble signs: green patches (Trichoderma), black spots, a sour smell, or a wet grey mass at the bottom from excess water. Slow, thin growth points to cold or old spawn. A bag hot to the palm is packed too tight or the room is too warm. Remove a contaminated bag at once and bury it in a deep pit away from the room.