The so-called "bad smell" in mutton is mainly composed of 4- methyl octanoic acid, 4- methyl nonanoic acid, C 10 decanoic acid, stearic acid and carbonyl compounds. These substances mainly exist in fat. To remove the smell of mutton, you can soak mutton in clean water for 2~3 days, and change the water 2 ~ 3 times a day to make the ammonia substances inside leach out. This can further remove impurities and odors in the blood. Of course, it is impossible to completely remove mutton unless it is roasted directly, because high-temperature roasting can melt fat, and the odor is mainly in fat. If the fat is less, it will become brittle, and the taste will naturally be less, which is why the mutton string has no taste. Other methods mainly rely on adding various spices.