The main causes of a low (poor) DOBI are:
• High percentage of black (unripe) fruit bunches
• Delay in processing, especially during rainy season
• Contamination of CPO with steriliser condensate
• Contamination of CPO with badly oxidised sludge oil
• Prolonged sterilisation of fruit bunches
• Overheating (> 55C) of CPO in the storage tank
There are other causes, but these are less significant compared with the above causes. These include splashing/aeration of hot oil, delay in processing due to temporary machinery breakdown, high-temperature crude oil clarification and high-temperature processing at other stages.