Question

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

Answer 1

Answer:

curd and sour substances are acids and brass and copper vessels are metals whenever metal react with acid they firm harmful compound liberating h2 gas...

Answer 2

$<v> Curd and other sour substances contain acids. Therefore, when they are kept in brass and copper vessels, the metal reacts with the acid to liberate hydrogen gas and harmful products, thereby spoiling the food.$