You can try the gutter oil. Waste cooking oil tastes different from normal cooking oil because it contains too much acidity, oxidation products or other impurities. Waste cooking oil often gives food an off-flavor, fishy smell, or makes people feel greasy and heavy. Skilled food professionals can identify the existence of waste cooking oil by smell or by trying. Gutter oil refers to the products illegally recovered and reprocessed by using waste gutter oil or other inferior oils. The production process does not meet the hygiene standards and contains a lot of harmful substances.