Why aren't you supposed to leave uneaten food in the can? [edited title]

Factual Questions
1

This is something that I’ve wondered for a while. In the UK at least every metal can you buy in the store says on the packaging that once then can is open you should remove the contents (beans, soup, tuna etc) before you store it in the fridge.

The thing is though, I don’t know anyone who put the leftovers in another container, they just stick the half eaten can straight into the fridge!

I’m just wondering if there’s some actual reason why you should do this? Is there some kind of health issue or is it just the food companies being over the top for legal reasons?

2

WAG but I think it’s a holdover from the days of unlined tin cans. The danger was from lead (which was used to solder the cans shut) that could leach into the food. After tin cans were replaced with aluminum and steel, the lead issue was gone but there may still have been some transfer of metal into the food leading to the metallic taste, and steel cans could rust, which is also unpleasant to eat. Most modern cans are lined to prevent direct metal-food contact.

3

I thought it was the modern lining that is the problem since it breaks down on exposure to air.

4

I never food in uneaten cans. I eat food from cans.

5

if your goats have eaten half the can i would just let them finish it.

also recently

6

I presume you’re supposed to food in an uneaten can because it would be pretty hard to food in an eaten can.

(But then I also think a canner can can a can and a canner would can wood.)

7

a whole can

8

The learning monkey is here to say, that fooding is easy and it’s ok.

9

Yeah, yeah, I’ve asked a mod to fix the thread title. :rolleyes: :wink:

10

I doubt it - at least not in the timescales wherein the food would still be edible… The lining is epoxy plastic, I think.

The problem is probably oxidation of the uncoated rim, where the can has been opened, or some sort of galvanic setup if you leave a fork or spoon on the often acidic contents, touching the rim.