Curd and sour substances should not be stored in brass or copper vessels because the acids present in these substances can react with the metals, leading to the formation of toxic compounds. These reactions can also corrode the vessels and contaminate the food, making it unsafe to consume.
Here’s a more detailed explanation:
Acidic Nature: Curd and sour substances, like lemon juice or vinegar, contain acids (e.g., lactic acid in curd).
Metal Reaction: When these acids come into contact with brass (copper and zinc) or copper, a chemical reaction occurs.
Formation of Salts: The acids react with the metals, forming salts (e.g., copper acetate if the acid is acetic acid).
Toxic Salts: Some of these salts can be toxic and harmful to humans if ingested.
Corrosion: The reaction also leads to corrosion of the brass or copper vessels.
Contamination: The toxic salts from the vessels can contaminate the curd or sour substance, making it unsafe to consume.
Spoilage: The reaction can also spoil the curd or sour substance.