Why should curd and sour substances not be kept in brass and copper vessels?

Curd and other sour substances should not be kept in brass and copper vessels. This is because curd and other sour substances contain acids which can react with these vessels to form poisonous compounds that can cause food poisoning and damage health.

Curd and sour substances contain acids. Acids reacts with metals to give salt and hydrogen gas. So, if such substances are kept in copper container, the acid will react and the container will be corroded.

Curd and sour substances contain acid. If we keep curd and sour substances in brass and copper vessel, Nitrogen gas and other harmful products are formed which spoil the food.