You're all shiny and clean, I've seen you in my dreams. Like the Rolls Royce I can't have. Your presence makes me scream. Sour grapes, you leave such a bad taste. Sour grapes, I don't need you anyways. Sour grapes, feeding, feeding my rage. Hey you, new wave, I pity you.

Why should curd and other sour foodstuffs (like lemon juice, etc.) not be kept in metal containers (such as copper and brass vessels)? Medium Solution Verified by Toppr

Metal + Acid → Salt + Hydrogen Lactic acid is an organic acid that contains the -COOH group. Hence, it is a weak acid due to the presence of this group. Lactic acid develops in cow milk because of the breaking down of bacteria. Fresh milk does not contain lactic acid. Dairy products such as yogurt, cheese and condensed milk contain lactic acid.