Abstract: A temperature monitoring method and apparatus for monitoring the temperature within a mass of organic matter moved through a composting vessel. An elongated, stationary probe extends through the vessel from one end toward another end thereof. A plurality of temperature measuring devices are mounted along the probe. The probe may extend through a compaction ram and be provided with a sleeve for accommodating movement of the ram relative to the probe. A decoupling device provides for decoupling of the probe from a mounting base and an extraction device permits the probe to be extracted from the vessel for replacement thereof. The probe provides a method of monitoring temperature in the mass and a method of composting by monitoring temperature in the mass and regulating the temperature of the mass in response thereto.