MAINTENANCE OF COPPER:
It can be done with a non-abrasive sponge and dishwashing detergent.
It’s better to not use abrasive sponge.
If some food remains attached to the pot, soaking the pot for one night and then clean as explained above.
Use fine salt (or yallow flour) mixed with vinegar (or lemon).
Rub with a sponge on the external side of the pot, rinse and dry.
This is very important to give shine to the copper, but is not essential: it possible to let the copper become brunished.
If in the bottom of the pot is visible some copper, is important to not use the pot and re-tinning it.