Record: Temperature and RH morning and evening, venting minutes, light hours, stalk and cap sizes, pinhead date.
Hang a thermometer and hygrometer at bag height in the middle of the room.
Vent for a fixed time morning, noon and evening; write the minutes.
Spray floor and walls, never caps; check RH an hour later.
Give 6-12 hours of light from a window or tube light.
Measure stalk length and cap width on five mushrooms daily; if stalks lengthen, add air first.

