On 01/06/2020 12:17, Chris Hogg wrote:
On Mon, 01 Jun 2020 10:23:35 +0100, Scott
wrote:

In the old days we used to keep opened tins in the fridge. I think
you could even buy a plastic lid to fit on the tin. Now we are told
to transfer the contents to another container.

Has the construction of tins changed, or is this another example of
excess caution? I have never known a tin to start rusting in the
timescale involved and even if it did, the rust would be at the top
not were the food is.

Decades ago, tin cans were coated with tin to stop them corroding. Tin
solder was also used to seal the seams, except when it recrystallises
at low, Antarctic temperatures, as the Scott expedition to the South
Pole discovered, to their cost. Most modern tin cans contain no tin.
They are internally coated with resin to stop the contents corroding
the steel.

when Gregg Wallace visited the Heinz vege soup factory in Bolton
I'm sure the employee he was talking to said the metal cans were
tin plated.

Everything you wanted to know about tin cans here
https://en.wikipedia.org/wiki/Steel_and_tin_cans
and
https://en.wikipedia.org/wiki/Tin_pe..._to_Antarctica