Two different variations of turning compost material in household composters were investigated and compared to controls that were not mixed. Compost processes took place under more favourable conditions in mixed composters, particularly where flies and bad odour were concerned. Mixing showed several significant influences concerning chemical and biological parameters. The speed of degradation as well as the qualify of the end product, was significantly increased through supported mixing with a mechanical stirrer In general, manual mixing also led to better results compared with static composters, bur differences were less distinct. (C) 1997 Elsevier Science Ltd.