So what is this “re-tin” that you do to copper pots and pans?
For those of you who don’t know what we’re talking about, I recently posted an article about How to Buy Pots and Pans. In it, I mention that I’ve retinned the inside of copper pots that I bought at a Bedouin flea market.
Copper is second to none when it comes to heating quickly and evenly. It’s thermoconductive properties leave aluminum and stainless steel in the dust. However, copper is also reactive, which means that when copper is exposed to an acid, it will release copper salts, which are toxic. So copper pots that are used to heat foods are lined with an inert metal, usually either tin or stainless steel.
By contrast, an unlined copper bowl used to whip egg whites will give you more volume than any other metal, and is perfectly safe, even with a pinch of citric acid, because it isn’t heated. No I don’t have one. My birthday is in June.
Tin has similar heat conductivity as copper, which is why it’s used to line copper pots. However, it wears away over time, leaving the copper exposed. So from time to time people with tin lined copper pots have to have the lining reapplied to the inside of their cookware. And, since looking up where to get this done in Israel would be total folly, not to mention more expensive than the pots themselves, I taught myself how to do it on my own.
The process is rather straightforward. You take ammonium chloride (sal ammoniac) and powder the inside of the pot with it, then melt pure tin (it has a very low melting point. A blowtorch or good stove will do), and wipe the melted tin around with a cotton cloth until the pot or pan is coated.
Now, dear readers, that doesn’t mean you should go out and try it yourselves based on my instructions. Just because I distilled three months of research into one paragraph doesn’t mean it’s easy, and it’s hella dangerous. Ever burn yourself with cooked sugar? Melted tin is 200 degrees hotter. If I find out you attempted this based on this article alone, I will hunt you down and beat you upside the head with a pot. A copper one. So don’t expect me to answer any follow up questions like, “Where do you get tin?” or “Where do you get a blowtorch?” Not gonna happen.