>>658158>>658124It is called "pressure canning". You place the hot food into hot boiled jars, put the jars into the pressure canner, with hot water in the bottom of it, and put on the lid & tighten it down. Bring the pressure up to 10lbs [240°F/115°C] or higher (depending on your elevation) for x amount of time for x type of food. After th time has elapsed, turn the heat off and allow the canner to cool until there is 0 pressure, but not negative pressure (or it will suck the contents out of the jars). Openning the canner while it still has pressure can be deadly.
Here's some good points to look out for in shitty online recipes for "canned" butter:
http://nchfp.uga.edu/questions/FAQ_canning.html#33Canning isn't dangerous in the slightest unless you are ignorant, stupid, have faulty recipe, have faulty equipment, or all the above.
When in doubt, use 10lbs pressure for 90 minutes if you are under 1,000 feet/305M elevation and 15lbs pressure if you are above 1,000/305M feet elevation. The only times you have uncertainty is with foods that are cut too thick or they are not liquidy enough. Butter doesn't have that problem. Examples would be large hunks of beef or pumpkin or pumpkin puree. The first two are simple too dense and should be cut to 1-2 inch cubes. The latter simply has to high a viscosity for proper flow and heat transfer to the middle of the product.
When animal products and mushrooms are involved, I always use 10lbs pressure and 90 mins to 110 mins (fish requires 110mins).
I use this manual with my pressure canners,
http://www.allamerican-chefsdesign.com/admin/FileUploads/Product_49.pdf>pics related and have been posted on /out/, /diy/, & /ck/ in the pastKeep in mind, some people are just ditsy/absentminded/lazy and shouldn't be unsupervised around pressure canners.
>>658297Heat+oxygen are the enemy for preventing rancidity of fats. Given enough time, fats can go rancid in the freezer. But, that normally takes years and poor packing methods.
