copper pots tinning & spots on chowhound site

To TJFrance and Kaleo
Hope you are able to read this
Grateful for your rapid response yesterday, 5/6/2017 when I went to chowhound site requesting help as to why the tin lining on my almost brand new tin lined copper frying pan ( used second time) from Bottega del Rame had a copper discoloration (?). I cooked exactly the same recipe of leek, S/P, garlic bulbs in EVO ,starting in a cold 350 degree oven for 90 min, but this time, I added a splash of balsamic vinegar , stirred it with a rubber spoon, then squeezed lemon juice prior to serving. I did not use any sharp object to serve either. I was desperate, losing all my enthusiasm for copper fever. ( 10 pieces within the last few months, the last one, just received 2 days ago a 5 pound 8.5 vintage windsor newly tinned by ECT . There was no maker mark except MADE IN FRANCE, heavy, cast iron handles with copper rivets. Jim at ECT advised me it is a fantastic piece at a very good price of $179) As Jim was not available being weekend. I sent a picture to RMT who was very nice, responded almost within an hour ( before both of you responded), advising me that it must be oxidation from the balsamic vinegar, not copper showing thru, to use 7gm baking soda/100 ml of water, enough water to cover the pot, bring it to a boil and dry. Within a few min after the water started to simmer, i saw the stain disappear! I logged in to CH to thank you both but spent hours trying to reply thru CH. I kept on changing my password 3 times, It turns out I could not confirm my status to reply. Hours later, found out that my email address is wrong (?) although I am receiving emails re other matters ! Could not change my email address ( one alphabet missing), tried to send them email etc, finally, re registered using new name, but could not be accepted bec my email address has already been taken!!!

ANYWAY, THANK YOU BOTH FOR THE GRACIOUS HELP. I HOPE YOU CAN STUMBLE INTO THIS PAGE!

1 Like

No problem. I have tried the baking soda boil, and while it lightens a little, not a lot. I will try that specific ratio (7g:100ml), though. Can you post photos?

Aloha,
Kaleo

Pictures not in order
Middle one shows before treatment

Wow, looks great.

I could see the stain disappearing even before the water came to a simmer.
Worried that perhaps the oven melter my tin but my vulcan range is fairly accurate.
WHAT A RELIEF
Tried again to reach TJFrance on Chowhound but still have logging in problem
Perhaps he comes to this site or you can forward this to Chowhound bec I have given up trying