Decades of soup will not go bad. Soup stock is the soup of stewed meat that has been used for many years, and some centuries-old soup stocks have even been used for hundreds of years. It can be preserved for a long time because of high salt content, sealing, freezing and repeated boiling and sterilization during use. Due to repeated stewing, some fresh and fragrant nitrogen-containing substances in meat will be dissolved in the old soup. Stewed meat with soup stock tastes more delicious, but the soup stock itself is not high in nutrients, but high in salt and purine.