You can do primitive canning without any electricity, but you’re going to need a few things.
Namely, a fire, a stockpot, glass jars, metal canning lids, and lots of sugar, salt or vinegar, depending on what you’re preserving. First, boil the glass jars and lids so they’re sterile. This is vital. If you don’t, you could trap bacteria inside your nice canned goods and end up with a terrible case of botulism if you eat the contents. Carefully remove them from the boiling water with metal tongs and let them cool enough to handle. Now, add more water to the pot and keep it boiling.
While the jars and lids boil, mix up your fillings. Fruit is best mixed with sugar and a dash of salt. Vegetables are best mixed with a lot of salt. You can also pickle nearly anything by adding a mix of vinegar and sugar. If you’re canning leftover soup, make sure you add extra salt to that as well. Salt is an additional preservative. Give yourself extra ammo against infection. Fill your glass jars nearly to the top and carefully return them to the boiling water.
The water should come up to the neck of the jars. Let the jars boil for 45 minutes. Using your nice sterile tongs, remove them from the boiling water and quickly screw the canning lids into place. Once they cool, they should be safe to put on a shelf and forget about for awhile.