Volume 4 Part 1 Article 31
Title: Peak-Heating and its Effect on Cropping Yields
Author: C . Riberrasmussen
The term “peak-heating” is only used in connection with mushroom growing. However, it covers such a wide range of techniques that no general rules can be laid down as to the correct methods to be applied. It is obvious that different peak-heating techniques have a marked effect on cropping yields as compared with no treatment, but drastically reduced yields may result from the use of incorrect peak-heating techniques.
Originally peak-heating was used for its natural “pasteurisation” effect and at temperatures which mainly depended on the heat generation of the compost itself (often combined with long-term outside fermentation) and without trying to reach a specific temperature. Later on temperatures were raised artificially by means of various sources of heat in an attempt to reach specific temperatures for a definite length of time in order to produce a suitable compost for spawn growth.
Peak-heating is now considered a true fermentation process and is carried out as such using controlled air introduction. Gradually outside composting has been reduced. Simultaneously the duration of peak-heating has increased. A number of mushroom growers use a short-term mixing process which acts as normal outside composting. The “compost” is filled and after 8-10 days of peak-heating the process is terminated. Very many different methods have been recommended (e. g. 1).