Tarnished silver isn’t dirty—it’s silver sulfide, formed when silver reacts with sulfur compounds in the air.
When you put silver + aluminum foil + baking soda + hot water together, you create a simple electrochemical reaction:
Aluminum is more reactive than silver
Sulfur “prefers” aluminum over silver
The sulfur transfers from the silver to the aluminum
The silver is reduced back to its shiny metallic form
In short:
👉 The tarnish moves from the silver onto the aluminum
That’s why the foil often turns dark while the silver brighte
What each ingredient does
ADVERTISEMENT