I was recently given some home canned fresh pork, that was preserved by boiling at 100C for three hours. It is only a few weeks old and tastes delicious, but after reading up on canning processes, I believe the above process is not safe.
The canned pork, along with the new confrontation the US seems to be provoking with Russia and imminent apocalypse, inspired me to look into canning my own meat.
As far as I can tell, the aim is to get the cold spot internal temperature up to around 120C for a while to kill clostridium spores, and it is not effective to use dry heat, because heat exchange is too slow and the cans don't like it.
The typical method I found online involves a water bath in a large pressurized container, to get the boiling point up.
I don't have a large pressure canner and I would like to do a large quantity of cans. Can i simply use a bath of vegetable oil maintained at around 130C?
UPDATE
As the answer and comments below describe, a pressurized can in a hot oil bath could explode and cause an eruption of hot oil. However, that leads to another avenue of thinking. PET bottles are designed to withstand high internal pressure, and would probably not melt at 120c (I need to check) but PET has high oxygen permeability. There are plastic canning jars such as these https://www.mycosupply.com/cgi-bin/shopper.cgi?preadd=action&key=PLID02 . But there is no data on internal pressure abilities. Is there a common container designed to handle high internal pressure that can be heated to 120C with low gas permeability? (beer bottles come to mind)
It seems beverage cans, especially those designed for in can pasteurization, would work https://hypertextbook.com/facts/2000/SeemaMeraj.shtml but those cans require expensive equipment.
UPDATE 2
So after more research, there is a process called Flame Sterilization, done at atmospheric pressure, and requires a smaller, robust can. However, the process is problematic and little used in industry. The trick would be to source cans intended for flame sterilization and then the oil bath would work. Any clues where from?
Best Answer
You are correct that simply boiling meat for three hours is not sufficient to make it shelf stable. Commercially produced, low-acid, canned foods must be processed to 240F just like home canned food. The process involves processing the cans in a steam pressure cooker similar to what is done at home at a smaller scale. 1
I have boiled sealed cans with but it is discouraged and I would not trust heating cans to 240F without matching the pressure outside the cans. Any can failure would be spectacular as the water instantly vaporizes and blows an easily-ignitable geyser of steam and oil into the air!
Pressure canners can be a bit expensive but can often be found used. You may need to replace rubber gaskets or safety valves but these are not expensive.
You may have more success canning using bottles as the bottles, lids, rings, and other equipment is easy to find for home buyers.
Another consideration is that canning recipes are written for specific pressures and cooking times to preserve food quality and give a very strong confidence of food safety. Even if you are confident your cans will hold, you would have to carefully control the temperature of your oil. Home sous vide controllers aren't designed for such high temperatures which means you would have to purchase a more expensive temperature controller or build your own.