Is it safe to store food in tin-lined copper?
I just made a marinara in a tin-lined pan, and I want to pop it in the refrigerator until Sunday, when I'll simmer it down just a little more and eat it. Is there any issue with just putting the whole pan in the fridge? I would expect that the tin will darken, but should I expect any change in the sauce that would be avoided by moving it to a glass container?
I wouldn't do it. It would probably be safe if the lining was *totally* intact and the people eating the re-heated foods were healthy adults. But as a rule, I'd avoid it. You can have exposed copper without appreciating it or its total area (hazy "wear-throughs" vs. easily-seen scratches). Tin itself is reactive, too, it's just that it doesn't make you sick.
And you picked about the worst food to consider doing this with.
I moved the sauce to another container last night. Fortunately this pan is freshly tinned, but I was concerned about the interaction of the acid and tin.
Let me ask you this: by the same reasoning dictating agains storing said sauce in the pan, would it be a bad idea to use tin-lined copper to make tomato sauce unless the lining is known to be fresh and intact?
"[W]ould it be a bad idea to use tin-lined copper to make tomato sauce unless the lining is known to be fresh and intact?"
No, I don't think so. I would put it differently: If you have reason to believe there is a total area of exposed copper bigger than a quarter dollar, I wouldn't cook anything in it (except maybe jam, candy or polenta), especially tomato sauce. But a small amount of exposed copper (e.g., a scratch) isn't going to be a problem for the length of time it takes to cook something like tomato sauce. It's the 23 hours it *sits* in the reefer I'd be concerned about.
I actually view this "Don't store in copper" rule to have a few incidental advantages: (a) It teaches you to wash up promptly; and (b) Your pans stay nicer longer between polishes.