dented cans...are they deadly??
Joe Slater
>Please excuse this question if it has been asked before, but I don't recall
>having seen it recently.....
>What is the truth about dented cans? My sister and I argued about this over
>thanksgiving dinner. Are cans that dented, bacteria laced or are they just
>cheaper in the damaged goods cart? I say that it is impossible (well, not
>entirely-anything is possible) for a can, through an accidently denting, to
>get bacteria inside.
This would be more appropriate on rec.food.preserving (where I have
crossposted and directed followups to), but here's what I know:
Cans used to be made by taking a sheet of steel, welding it into a tube
and welding a disc onto its base. After filling it with food you would
then weld another disc to close it. If this sort of can was dented the
seam could easily buckle, creating a gap through which bacteria could
enter.
Modern cans are usually made by taking a tube of steel (i.e., one without
a seam) and sealing it at the top and base. These are much less likely to
buckle and allow bacteria to enter, because it's easier to make a solid
right-angle seam than a flat one. It's also mechanically stronger at the
rim. Some cans are actually made of only two parts, like the ones used for
soft drinks, and these are safer yet.
Basically, I'm not worried about dents on the *side* of modern cans
(although I may be worried about dented rims). I'm worried about all cans
made using the old welded-side method, which are still made at some old
plants.
Cans should have a semi-vacuum inside - they should suck air in when you
open it. If the contents have a foul odour or spurt gas or liquid out,
discard the can immediately.
In a vain attempt to make this more relevant to AFU, here's a little
trick you can do which will amaze your friends if they're easy to amaze:
Take a can, and hold it on its side, with your fingers wrapped around the
top of the curved portion.
Place a finger on the edge of the table, pointing towards its centre.
In one smooth movement, bring the side of the can crashing down, so that
the centre of the can's side impacts your finger. It should deform around
your finger without causing pain. If it doesn't, you have probably used
the top or base of the can and amputated your finger instead.
If you do this slowly the can will not deform, and you'll have a sore finger.
I've never hurt myself doing this, but it's not my fault if you do.
jds
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