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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?

  • Creative idea, and I'm curious to hear what people say, but I wonder, without the pressure, wouldn't the water contained in the meat start steaming out at 100 C, and retard the further heating of the meat up to the target temp of 120 C? – Lorel C. Apr 11 '18 at 21:32
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    @Lorel C. Actually after I posted the question I realized that the can itself would become the pressurized container and the steam would rise to 120c under pressure, assuming the can remains sealed. The question then becomes whether or not the can can physically stay sealed, otherwise an explosion of steam in a bath of hot oil could be a safety issue. – Sentinel Apr 11 '18 at 21:35
  • @Lorel C. If the steam leaked, I imagine the meat would cook anyway to 120c but would be dry. – Sentinel Apr 11 '18 at 21:37
  • It will be very very dangerous if you rely on the can to maintain pressure due to the lack of over-pressure protection. – user3528438 Apr 12 '18 at 1:24
  • @user3528438 after a lot of digging it seems this is doable with the right type of can. I don't know how to identify a supplier though. I would need to find the specs for cans that used to be used in flame sterilization. – Sentinel Apr 12 '18 at 6:09
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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.

  • Thanks for the useful information, but I will not mark as accepted yet, I updated my question as this raises some new ideas and questions. For the temperature controller, a thermometer and patience. – Sentinel Apr 12 '18 at 4:54
  • That would work but It is more patience than I have to watch a thermometer intently for 90 minutes. – Sobachatina Apr 12 '18 at 13:28
  • I think it would actually be pretty easy to connect a thermostat to a relay and submerge the thermostat in the oil, and probably quite cheap. The thing is finding those cans, the ones for Flame Sterilization, otherwise (as you rightly point out) the cans can cause a hot oil geyser if they leak or burst. – Sentinel Apr 13 '18 at 7:37
  • I agree that making your own temp controller isn't difficult. You've demonstrated above average aptitude for it just by knowing the word "relay". I am interested as well when you find out about the flame sterilization cans. – Sobachatina Apr 13 '18 at 13:33
  • Maybe a raspberry pie would do it ;-) – Sentinel Apr 13 '18 at 14:43

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