1. The solution to the blackening of raw materials after bittern is to add less sugar to bittern. Don't add too much red rice. If you add too much, the color will look good when you first come out of the pot, but it won't last. Also, the marinated vegetables bought outside are added with antioxidants, so don't leave them at home. You can add some if you sell it. The main reason for blackening is that raw materials are oxidized.

2. Salt water materials: (meat products)