1, don't turn off the fire, let the soup be cooked on the fire all the time, once in the morning and once in the evening.

2, freezing, filtering the soup stock after cooking, freezing the soup stock, and then cooking at least once a week.

3. About soup stock or soup stock. Although the old soup or broth has been circulated for hundreds of years, water and new ingredients will be added every time the remaining soup is used, which can dilute the concentration of nitrite, and the old soup or broth will be heated repeatedly every day, which can kill possible pathogenic bacteria. Therefore, a pot of soup in this old shop will continue to be used, and people will generally not affect their health.