Recovery on top of the beds after ruffling or after the last application of water is often irregular. To encourage recovery the air temperature is frequently allow to rise to 23 degrees Celsius with the fans switched off for the last 12 hours. Compost temperatures often then rise to 28–29 degrees. Blow down at these high compost temperatures means much moisture is lost from the casing soil and as it takes so long before the compost temperature drops below 23 degrees Celsius, the casing soil becomes fully colonised by mycelium. Pin heading and further growth is often problematical and in the second flush quality problems occur caused by too dry casing soil with excessive mycelial growth.
Ensure when the casing soil is watered for the final time that the compost temperature is lowered to 24-24,5 degrees Celsius and set the maximum air temperature during recovery to 21 degrees. Activate the cooling system if necessary. The maximum compost temperature at the start of blow down is 26,5 degrees Celsius. If the casing soil surface is still too dark lower the air temperature slightly more gradually than normal (+ one day extra) and keep RH around 94–96 % An added advantage with a lower compost temperature is fewer problems with green mould if it occurs in the compost.
Jos Hilkens, AdVisie ‘The mushroom cultivation advisors’