A process generates smoke by controlled combustion of wood fuel held within a hopper and fed to a combustion chamber. When spent, fuel residues are scraped out and released. The temperature of the burning fuel is continually monitored and compared with the required process time-temperature profile, and that spent fuel residues are removed as required to maintain the temperature at the required level. Also claimed is a smoke (R) generating assembly (10) which holds the smouldering fuel (B). The fuel (B) gradually descends to the assembly (10) base (14), and is raked (20) out through the grate opening (14a) as required. The temperature is monitored by a thermometer (30).
