Mixture 2 yielded the optimum percentage of methane gas on the 22nd day with 49%. However, fl uctuations were observed on the 31st, 34th and 37th days. For Mixture 3, the optimum methane was produced on the 25th day with 46%. In general, the graph for Mixture 3 is stable because food waste content and sludge are balanced (1.5 kg: 1.5 kg).