Do salt and vinegar dissolve copper?

Can salt and vinegar actually clean copper?

Have you ever noticed how old pennies or copper pots lose their bright, shiny finish over time and turn a dull, brownish color? That outer layer is called copper oxide. While plain water can eventually wash away some surface dirt, it barely makes a dent in that stubborn tarnish on its own.

That is where a classic kitchen science trick comes in. When you mix vinegar—which is a weak solution of acetic acid—with common table salt (sodium chloride), you get a powerful natural cleaner.

Individually, neither ingredient works miracles on heavy tarnish, but together they team up to dissolve the copper oxide layer. The acid in the vinegar and the chloride from the salt react with the copper oxide, creating soluble blue copper(II) ions that easily wash away in water. This quick chemical reaction strips away the dull buildup almost instantly, revealing the bright, metallic shine hiding underneath.