Copper tarnishes over time if it doesn’t have a protective coating, and ends up looking dull and dark. This is because when copper is exposed to air it develops a layer of copper oxide which dulls the surface. Some people like this patina of age, but if you prefer your copper pans bright and shiny, there’s an easy way to restore them to brightness without resorting to toxic chemicals.
In this article we look at four of the most popular methods for cleaning copper pans using only eco-friendly ingredients:
Cleaning copper with citric acid
Cleaning copper with vinegar and salt
Cleaning copper with lemons and salt
Cleaning copper with tomato ketchup
Cleaning copper without toxic chemicals: summary
Useful supplies for cleaning copper
Non-toxic copper cleaning options
All you need to remove the discoloration from copper is a combination of a mild acid and a gentle abrasive. You probably already have some items in your store cupboard which are suitable for cleaning copper, for example:
white vinegar (acetic acid) and salt (as the abrasive)
some half lemons (citric acid) and salt (abrasive)
tomato sauce (contains acetic and some citric acid) plus the use of a gentle scouring pad for abrasion
However, our top eco-friendly method is to use food grade citric acid to clean the copper, as this provides both the mild acid (the same as in lemon juice) and the necessary abrasive element at the same time. This method works really quickly and doesn't require much elbow grease. Plus you don’t end up wasting loads of lemons!
Caution: Remember that copper is a fairly soft metal, so whichever method you use, avoid excessive scrubbing or harsh scourers as these can scratch or even wear away the metal. We found that with the best two cleaning options, nothing more than a soft cloth was necessary to apply the cleaning mixture.
Cleaning copper with citric acid
Before you start you need to wash your copper pan (or other copper item) in warm soapy water to remove any grease or dust. Then:
Mix up a paste consisting of citric acid, a drop of washing up liquid (to make the paste more sticky) and a little water. Mix the ingredients together well to form a soft spreadable paste.
Spread the paste in a thin but even layer over the base of your pan. You may find this easier to do in the kitchen sink as you will need to wash the paste off afterwards. The citric acid will start getting to work immediately, but if you leave the paste in place for five minutes or so, the results will be even better.
After around five minutes, wipe off the paste with a damp cloth. (The paste may have gone crusty depending on how thick you made it but that’s OK). You should now have a copper pan with a clean and shiny bottom, for minimal effort. If any tarnish remains, rub it with a little of the paste on a soft cloth.
Now work on the sides of the pan, by rubbing the remaining paste into the copper with a soft cloth. There's no need to scrub hard, the acid in the paste does most of the work. If there's a badly discoloured area, try applying a layer of paste again and leaving it to get to work for another five minutes.
When all the tarnish has disappeared, give the pan a good rinse to remove any last traces of the citric acid paste, then buff to a golden, shiny finish.
You should now have a bright and shiny copper pan, without using any toxic chemicals.
Cleaning copper with citric acid: video
For a demonstration of how you can use citric acid to clean a tarnished copper pan, watch our short video:
[Music credit for video: Music: Dear Autumn; Musician: @iksonmusic]
Cleaning copper with vinegar and salt
Another eco-friendly and effective way to clean copper is to use white vinegar (also known as distilled vinegar) and salt. As with the other cleaning methods, begin by washing your copper pan in warm soapy water to remove any grease and dust. Then:
Place your pan upside down in the kitchen sink and sprinkle an even layer of salt over the base.
Sprinkle some white vinegar over the layer of salt, taking care not to wash the salt away. (We found that the best approach was to put some vinegar in a small spray bottle, and to use that to spray the vinegar onto the salt.) If you have washed any of the salt away, sprinkle on some more.
Leave for a few minutes so that the acetic acid in the vinegar starts to work on the tarnish on the bottom of the pan.
With a soft cloth, rub the salt and vinegar mixture over the bottom of the pan. You shouldn't have to scrub hard - the acetic acid in the vinegar reacts with the oxidisation to remove it, while the salt provides a gentle abrasive to help with stubborn areas.
Continue to clean the sides of the copper pan with the vinegar and salt mixture, rubbing it into the metal with a soft cloth.
When all the tarnish is removed, rinse the copper pan well to remove any remaining traces of the vinegar then buff to a shiny finish with a dry cloth.
Cleaning copper with lemons and salt
Cleaning copper with lemons and salt somehow feels like the most eco-friendly option, however it requires rather more effort than either of the citric acid or the vinegar methods. This is because the acid in the lemon is less concentrated so you need to scrub more to shift the tarnish.
As above, begin by washing your copper pan. Then:
Turn your pan upside down and sprinkle the base with a little salt.
Cut a lemon in half, then use the cut side of a half lemon to scrub the salt into the base and sides of the pan.
Keep going.
Add more salt as necessary, and swap to the other lemon half if the first one wears out.
For particularly tarnished areas, try leaving the cut side of the half lemon over the area for a few minutes so that the citric acid can get to work.
Eventually you will have a bright and shiny pan. Be sure to rinse the pan well when you've finished.
Cleaning copper with tomato sauce
Yes, you really can use tomato sauce (ketchup) to clean the tarnish from your copper pan. This is because tomato sauce contains acetic acid, and a little citric acid too. However it is quite messy and is not as quick or as effective as the citric acid or the vinegar methods described above. But it will work if you have nothing else. This is what you do:
Wash your copper pan first.
Place your copper pan upside down in the sink.
Spread a layer of tomato sauce over the base and leave it for at least 10 minutes.
Wipe a small area off to see if it has removed the tarnish. If it hasn't, leave it for another 10 minutes.
When you can start to see bright areas under the tomato sauce, wipe it off with a soft cloth. If areas of tarnish still remain, scrub them with a gentle scouring pad (eg a sisal or loofah scourer) and some more tomato sauce. Do not use harsh or metal scourers on copper as these will damage the metal.
Repeat for the sides of the pan.
When you've removed all the tarnish, wash the pan well and buff to a shiny finish.
Cleaning copper without toxic chemicals: summary
To clean your tarnished copper pots and pans the non-toxic way, all you need is a mild acid and a gentle abrasive, however some methods are quicker and more effective than others. Our opinions on the commonest methods are:
Citric acid: Our favourite method - quick, effective, minimal scrubbing required.
Vinegar and salt: Also effective with minimal scrubbing, just a little more fussy with needing to have the salt as a separate abrasive.
Lemon and salt: Will clean your copper pan eventually, but requires quite a bit more effort with the scrubbing than with the previous two methods (also wastes perfectly good fruit!)
Tomato sauce: Works if you have nothing else, but it's messy and quite slow.
More information
For ideas and instructions on making other homemade cleaning products:
See also our blog posts: