Definition and use of casing

A tough translucent film made by scraping the large and small intestines of livestock. It is divided into pig casings, sheep casings and cattle casings according to animal types, and can be divided into small casings and large casings. It is mainly used as a coat for filling sausages and enema; sheep casing can also be made into gut for making tennis racket string, bow string, instrument string and surgical suture, etc. China has been processing casings for more than a hundred years. Pig casings are mostly produced in Eastern and Central China; sheep casings are mostly produced in North China, Northeast China and Inner Mongolia. Initially it was only used for bowstrings and cotton strings, and the output was limited. At the beginning of the 20th century, factories were set up in Tianjin, Beijing and other places for processing and production, which soon became an important export material for China.
constituteFrom the inside to the outside, the intestine can be divided into four layers: mucosa, submucosa, muscle layer and serosa. When processing the salt casings of pigs and sheep, only the submucosa is left and the other 3 layers are scraped; when processing the dry casings of pigs and sheep, part of the mucosa is retained in addition to the submucosa; when processing salt and dry casings of cattle, only the mucosa is removed And keep the other 3 floors. The processing process of salt casings is roughly as follows: wash the fresh intestines, soak them for 18-24 hours and then peel them off. Then rinse, water test, cut off the damaged intestine section, make every 5 or 10 pieces (total length of about 90 meters), salt with about 0.5 kg of refined salt for a day and night, it becomes semi-finished intestine. The light intestine is then further processed by rinsing, inspection, repairing, salting, and draining to become a finished product. The processing process of dry casings is roughly similar. After stripping, add 2.5 liters of 5% sodium hydroxide solution for every 70-80 roots and stir evenly to remove grease; after rinsing, use 0.8-1 kilograms of refined salt per 100 meters to salt 12～ After 24 hours, wash with water to remove the salt, dry, and flatten, then it can be wrapped into bundles and sold in boxes. High-quality pig casings are thin, tough, transparent and uniform (sheep casings are better); salt casings are light red, white or milky white. Dry casings are mostly light yellow; they have a certain aroma.