Tuna tins aren’t. Neither are any other tins of anything, that I can tell. And they all seem to stack together well, so it’s not that.
So, why are tins of salmon tapered: thicker at the top and thinner on the bottom?
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Exaggerated view, but you get the picture.
Is it because they don’t want you using the lid to squeeze out all the moisture? Every brand, including no-name is like this.
They are shaped that way because the salmon is placed (with water) into the cans raw, then they are heat processed and sealed. The shape of the can helps to keep it from deforming as the temp/pressure drops inside as it cools. This is also the reason that sardine tins are shaped the way they are.
regards
The salmon is cooked?
What about tuna?
And what’s so special about sardine cans?
Wild salmon like sockeye and pinks are seasonal fish that are only harvested and processed for a couple of months a year at any one location. Processing plants do not manufacture cans onsite; it is cheaper to ship them in for the short packing season than invest in can manufacturing machines that are only used for a short time. The cans are tapered so they will fit inside each other when shipped empty from the manufacturing plant to the many local packing plants. This takes up much less volume than untapered cans.
In the can.
Cooked. In the can.
Generally speaking (and aside from obvious exceptions, like pop) you can assume that anything sold in a can is cooked. The cooking kills any bacteria present, and the sealed can stops any more getting in.
This is the whole point of canning.
Where are you finding these tapered cans? Here in London I don’t recall salmon cans that were anything other than cylindrical.
All salmon cans are tapered here in Australia too, but not so for tuna or other canned fish. I always thought it was because the salmon was put into the can as a whole fillet of fish…IOW, the spine was in the middle and the fillet filled out the can. With tuna et al, it’s just put in as flakes, so no tapering was necessary.
Of course, I might be wrong…it’s happened before 
The salmon cans I’m talking about are only about two inches tall though, twice that of a tuna can, and also just flaked or chuncked: not the whole salmon.
Fear Itself makes a good point, but I don’t imagine most places that do canning have their own on-site can manufacturing facility. Surely the vast majority of cans are manufactured off-site and shipped, and they’re not tapered.
And if tuna is also heated in the can then why aren’t those cans tapered too?
Voila!
…which is what Fear Itself said in post #4!
Yes. I added the link and quote after the fact. Fear Itself was correct.
Say what now?
Round these parts, tuna and salmon come in identical tins. And have for as long as I can remember. I just assumed it was the same everywhere.
Yeah, I’ve never noticed any difference between tuna cans and salmon cans.
(I skipped over this thread twice before realizing that the question was about tins and not fins.
