You’re better off just buying an array of nutritious canned goods. Somebody up in Alaska already crammed a salmon into a can and cooked it for your convenience. Just don’t forget your can opener.
I think wanting to know how to can food is a good thing, it’s not necessarily expensive if you already have the jars and canning supplies, can be done over an outdoor wood fire as I noted above. If you don’t have jars and canning supplies it’s gotten expensive. If you’re concerned over some sort of economic catastrophe, those store-bought canned goods put back will only last for so long, then you’re on your own and will need some means of preserving what you produce to tide you over the winter. Develop a taste for turnips, I suggest. Apples, too. Learn how to dry them on a screen and you can make apple pies, apple butter, apple cobbler, all winter long.
Buy a pile of military P38 can openers scatter then around your life to make sure that never happens.
http://olive-drab.com/od_rations_p38.php
https://www.amazon.com/U-S-Opener-Pack-Military-Issue/dp/B00DMSQT5M
Can opener not necessary for metal cans. I’ve done this for years and even a toddler could do it.
Rub the top of the can where the lid is crimped on to the body of the can on cement sidewalk a few times until the top lip is worn down. You only have to grind through a thin piece of metal. Once you’re through, remove the lid and drink your cold chicken noodle soup. This method is shown on youtube. can get through a can faster than with the P-38.
Primitives did not can, they dried. Natural fermenting is another way but not a long term solution (no pun intended).
Canning also does not have an infinite shelf life. Granny canned to feed the family until the next season of crops were ready for processing.
Yeppers.... I believe caned salmon has a shelf life of five years...it would last longer then that if you can keep the can from rusting... Lots of protein and nutrients there...