Why Copper Turns Green

And Why Your Copper Sink Won’t

People often ask us if our copper sinks turn green. The short answer is “nope!” Copper is a living metal, meaning it has a wonderful capacity to protect itself from the elements.

When copper encounters the oxygen in the air and trace minerals left behind by water, the surface of the copper naturally combines with these elements to create a thin protective coating called the patina. Copper’s patina gradually becomes richer and darker, creating a lustrous finish with rich veins of color and depth.

Time and continuous contact with trace minerals left by water are what cause copper to turn green. It is protecting itself from the minerals and possible corrosion.


Pennies, new and with patina, on Tempered Copper

Customers often ask us how to clean their sink. Maintenance is as easy as wiping it down with soap and water and drying it off. The patina process has already started with the antique finish, and to some degree, with the tempered finish. Your copper sink, like a frequently-used penny, will continue to patina over time and become visually richer and more beautiful, without turning green.

When looking for a copper sink, be sure it is made of high-quality copper, whether reclaimed or newly mined and is made by a reputable company with third party certifications. This ensures that the copper is not contaminated by lead or other impurities that might cause it to discolor in an undesirable way.

Also, don’t worry if you left a lemon or lime and your sink turns shiny. In just a few days, the brown copper patina will form and soon the spot will be gone.