Production Conditions

After spawning, the bags or bottles may be moved to a spawn run room where air temperature is maintained at 18–20°C. Relative humidity is maintained at 95 to 98 percent to minimize drying of the substrate surfaces. Only recirculated air is used for cooling and air distribution. The first 12 to 21 days of spawn run may be completed without artificial lighting. Spawn run in bags usually requires less time (depending on the amount of spawn used) than spawn run in bottles. This is because spawn is thoroughly mixed in substrate contained in bags.

For bottle production, the spawn is placed in a hole made in the center of the substrate contained in the bottle, so mycelium must have enough time to reach the edges of the substrate before pinning is initiated. This difference may only be 3 to 4 days. At the end of the spawn run period, 4 hours of light may be provided daily by cool white fluorescent bulbs. Light intensity, measured at various locations in the growing room, may range from 50 to 300 lux, and the lighting cycle often is controlled automatically. At time of pinning, sufficient fresh air is introduced to lower CO2 levels below 700 ppm.

2992 view.