You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.

Lemon and tamarind clean tarnished copper vessels because they contain acids like citric and tartaric acid. These acids react with the dark copper oxide layer formed on the surface and dissolve it, revealing the shiny copper underneath. The mild acidity is strong enough to remove tarnish but safe for the metal, which is why these natural cleaners work so well. For high-quality copper and brass vessels that stay bright longer with proper care, http://www.brassglobe.com offers excellent handcrafted options.