Shark fin hair method: when making shark fin, we must first separate the old from the young, so as to master the heat separately to prevent the young from rotting and the old from being cooked thoroughly. Large and old shark fins are generally thick and sticky, with high quality, but because of their large fins and old skin, the sand is hard to fade. Therefore, the thin edge of shark fin should be cut off first to prevent sand from entering the wing when it expands; Then soak it in cold water for 10 ~ 12 hours to soften it, then put it in a boiling water pot for 1 hour, then stew it in boiling water until most of the sand grains swell up, scrape it with a scraper to remove the sand grains, and scald it again with boiling water if it is not cleaned. Then separate the shark fins according to the degree of hardness, put them into bamboo baskets, cover them and stew them in a pot to prevent them from being crushed by boiling water. Hard stew for 5-6 hours and soft stew for 4-5 hours. Let it cool slightly after stewing, and then stew for 1 ~ 2 hours. Pay attention to the inspection in the process of stewing until the hair is completely taken out, rinse it with clear water and remove the odor for later use. Small and tender mixed wings. Generally, the wing plate is thin and hard. Sand grains are also difficult to remove. It is advisable to cook less and stew more. Cut off the wings first. Put them in the lid and boil them in boiling water. After the water temperature drops, change the boiling water and soak it again until the sand can be scraped off. Then cut off the wing root and separate the soft and hard parts. Put them in bamboo baskets, stew them in a pot for 3 ~ 4 hours, cool them a little, and then remove the bones and carrion. Pay attention to check when stewing. Stew it thoroughly inside and outside before taking it out, washing it and waiting for use. Don't put the prepared shark's fin in iron, or it will cause yellow spots on the shark's fin due to chemical changes, which will affect the quality. Hairy shark's fin should not be soaked in water for too long, so as not to stink and deteriorate. Note: 1. Pay attention to material selection. No matter what grade of shark fin is used, moldy and deteriorated shark fin can't be used. 2. When soaking, be sure to change the warm water frequently, at least 3 times, so as to avoid the deterioration of shark fin due to water odor. Be sure to use two bamboo basketry before shark fin stew. In doing so, one is to avoid shark fin being smashed, and the other is to avoid shark fin deformation and decay. 4. Pay attention to the time when simmering. Old hard shark fin is usually stewed for 5 ~ 6 hours; Soft shark's fin usually needs to be stewed for 4 ~ 5 hours. The time for stewing shark fin should not be too long. If it is too long, the surface of shark fin will easily fall into sand due to cracking. Of course, the simmering time should not be too short, otherwise the black outer film and sand particles can not be removed. 5, simmer, simmer pot method should be adopted, can't open the pot. If the fire is big and the water boils, it is possible to boil the surface of shark fin, and the surface of shark fin will rot, and the meat of shark fin will be mixed with sand, so it is not easy to scrape the skin and remove the sand. In addition, shark fins should be separated according to their size and tenderness before making, so that they can be made separately, otherwise the small and tender shark fins will be rotten and the old and strong ones will not be done thoroughly. 6. you can't use iron pots and copper pots to simmer shark fins. As sulfur protein is contained in shark fin, it will react with iron and copper to generate iron sulfide, which will cause black and yellow spots on the surface of shark fin and affect the quality of finished products. When making shark's fin, it is recommended to stew it with porcelain pots, stainless steel and other utensils. 7. When the shark fin is simmered, or after the shark fin is made, you can't touch oil, alkali, salt and other substances, otherwise it will cause the shark fin skin to melt and affect the quality of dishes. 8. After the shark's fin is simmered, gently pick it with a bamboo stick when removing meat and bone residue, and try to keep the shark's fin tidy so as not to affect the beauty of the dishes. 9. After removing bone residue and sand from shark fin, it should be washed repeatedly and continuously with clear water. One is to wash off bone residue and sand, and the other is to wash off fishy smell.