My mom and dad still can sausage. I say "can" They fry sausage balls, a little smaller than a golf ball, and when they are almost fried out, they pour the hot greas on top of the sausage balls in a pint jar. they ten screw on a lid, turn upside down, and let them sit. the air in the jar can not have any bad stuf....it was hot.ditto the sausage and grease. The greasr forms an air sel. No one i know has ever gotten sick doing canned sausage this way, though it breaks all the rules. If I understand right, French peasants would cook a goose, and pack the meat in a crock. then pour hot goose grease over it. IKNOW the susage benefits from this treatment. more tender, mellow, indescribable, really. they say the goose was a lot better after "curing", or sitting this way for a while.
We used to make jelly like that, too. put it in jars, and pour hot wax on top, making a seal. people today would not eat anything like that, but i sure got fat on it. Course we drank unpasturized milk, ate ice cream with real, raw eggs, and didn't know ther was such a thing as a bycicle helmet.