Once white mycelium covers the bed, the sheet is removed and the bed changes from growing to fruiting. DMR now asks for 28 to 32 °C and about 80 percent relative humidity. Keep humidity with a fine mist on the floor and walls, never a direct spray on the bed, which rots the pins.
Give the bed light and a little fresh air. For indoor beds DMR lists fluorescent light and intermittent fresh air. In a film house TNAU works at 25 to 35 °C and 75 to 80 percent humidity. Expect the first mushrooms 4 to 5 days after the sheet comes off; TNAU sees tiny buttons in 6 to 10 days and picks 4 to 5 days later.