Why should curd and sour substances not be kept in brass and copper vessels?
Curd and other sour substances contain acids. Therefore, when they are kept in brass and copper vessels, the metal reacts with the acid to liberate hydrogen gas and harmful products, thereby spoiling the food.
Curd and sour food substances contain acids; these acidic substances have a possibility of reacting with the metal. If this reaction takes place then it can cause food poisoning and damage people’s health