A method to process grease trap waste or refuse and remove organic matter, and reclaim fats, oils, and grease (FOG) found in it. The process is initiated after dewatering the grease trap material to increase its concentration; the resulting sludge is then mixed with a solvent. The dissolved fractions of fats, oils, and grease are separated using mechanical methods. The solids are washed to further remove any traces of fats, oils, and grease. The solids, substantially free from organic content, are dried to remove any water and/or organic matter remaining, rendering inert solids that can be safely disposed of according to Environmental Protection Agency (EPA) regulations. All fats, oils, and, grease fractions are separated, containing no inert materials, and no water. The solvent is recuperated (recycled), allowing it to be used over again. The recuperated grease fractions, highly pure and homogeneous, constitute an excellent raw material for further oleo-chemical processes and applications.