The bleaching of edible oils and fats is a part of the refining process of crude oils and fats, which removes contaminants that adversely impact the appearance and performance of these triglyceride (triacylglycerol)-based materials.

The bleaching operation effectively removes some of the colour, reduces the contents of chlorophyll, residual soap and gums, trace metals, oxidation products, and indirectly impacts on deodorized oil colour. While the bleaching process appears to be a simple mixing of bleaching earth and oil, the mixture of oil and bleaching earth is pumped through pressure leaf leaf filters with stainless steel mesh elements followed by polishing filtration.

Spent cake is dried by steam blowing to remove the oil from the wet cake.